Audio problem: When Lindsay learns that Tru has broken up with her secret boyfriend and met another guy the same morning, she jokingly whispers to her, "You little slut." The movement of her lips doesn't match at all.
Continuity mistake: The first time Tru lives the day, she has breakfast with her brother first thing in the morning. Harrison goes to put sugar in his coffee and the lid falls off. The second time, they go out together much later (after Tru goes shopping with Lindsay), and Tru manages to grab the sugar lid just before it falls off. But people have been eating at the restaurant all day, so it's not at all likely that the lid would still have been loose. Plus, the same patrons are seen in the diner even though it should be a completely different crowd.
Character mistake: At the end of the episode, after Sarah has been tricked into revealing her plan and is rather obviously going to go to jail, Tru tells her that she "should have taken half," meaning that she should have settled for half of Andrew's money in a divorce instead of trying to get all of it by having him murdered. But Tru seems to be forgetting that Sarah has been trying to divorce Andrew all along, and it's Andrew who has stood in the way of that. Sarah would evidently have been perfectly happy with half, but Andrew prevented it from even being on the table for her, so Tru's comment doesn't make any sense.
Continuity mistake: The second time the day happens, the man stands up in the restaurant to profess his love to his girlfriend almost immediately after the waiter drops his tray. There is only about ten seconds between the two events, but the first time it all happened, there was a gap of nearly thirty seconds.
Plot hole: When Marco brings Andrew's corpse to the morgue the first time the evening happens, he says that Andrew was died "in his ex-wife's house." However, during the second instance of the day, it is eventually revealed that Sarah is actually still married to Andrew, and they are just separated. Sarah may have lied to Harrison about that, but the police would have gotten accurate information. In fact, when Sarah calls the police (the second time), she refers to Andrew as "her husband."
Past Tense - S1-E4
Plot hole: When Lindsay brings Tru breakfast in bed on the second version of the day, she is excited that Tru remembered her birthday, and she also mentions that nobody else did. But it's still very early in the morning. It's not at all reasonable to assume that anybody forgot her birthday just because they didn't call before 8am.
Past Tense - S1-E4
Factual error: Davis tells Tru that glucagon is a substitute for insulin in diabetic emergencies. In actuality, it does exactly the opposite of insulin, raising glucose levels in the blood while insulin lowers them.
Past Tense - S1-E4
Plot hole: Meredith is subjected to a random drug test at work. However, the drug test is announced late at night. Tru is already working her "graveyard shift" at the morgue, so we know the regular workday is over. Hardly anyone would be in the office. Therefore, it doesn't make sense for the company to be administering this drug test, said to be requisite for all employees, at that time.
Past Tense - S1-E4
Plot hole: Meredith submits to the drug test at her office. In the next scene, which takes place later the same evening, Harrison tells Tru that Meredith's test came back positive and she was immediately fired. But it takes at least 24 hours to get a result from a urine test at all. If the test is positive, the sample must be subjected to a more thorough examination. It usually takes at least 72 hours to get the results in that case. There's no way Meredith's positive results could have come back in less than six hours, even if a lab had been open late in the evening.
Past Tense - S1-E4
Plot hole: John is slightly surprised to find that Tru is acting as bartender for the party, but doesn't dwell on it any further once she explains that she was supplied gratis to make up for the earlier "problems" with the room. But John should actually be extremely alarmed to find her there, given that he poisoned the ice and expects the other guests to drop dead. He certainly wouldn't want any witnesses to that.
Factual error: Tru arrives "more than three hours late" for the MCAT and then begins the test. Firstly, it would be pointless for her to even bother going at that time, since she'd have already missed the entire Verbal Reasoning section and possibly the Physical Sciences as well (depending on how much more than three hours she was late). Secondly, that's really a moot point since late arrivals to MCAT testing centers are not permitted to take the test.
Plot hole: The invigilator at the MCAT tests is sloppy. You can't hand somebody paper, even if it's only a tissue, during the exam.
Factual error: Both Tru and Davis refer to the petechial hemorrhaging (i.e. the bleeding behind Paige's eye-lids) as 'petechial imaging' at least twice in the episode which is very shabby given their experience working in the morgue.
Revealing mistake: It was raining in Vancouver the day the outdoor scenes were filmed for this episode, so the actors were filmed under large tarps. When Tru and Paige walk together in the park, rain can occasionally be seen in the foreground and background, but not over the characters themselves. The ground is also wet everywhere throughout the episode.
Continuity mistake: Near the end of the episode, Paige asks Tru something along the lines of "aren't you going to tell me your real name?", showing Tru hasn't told Paige her name yet. But then Paige says "goodbye Tru" at the end of the scene.
Continuity mistake: The clock in the MCAT testing room reads 10:55 when the test starts without Tru, and 5:05 when the proctor tells Tru that she's more than three hours late. But by those clocks, she's actually more than six hours late.
Plot hole: There's too much bruising on Paige's arm in the original timeline, given that she only had one injection given to her by a med student (on the day of her death). She doesn't appear to have had any previous injections when Tru looks at her arm in the second timeline.
Plot hole: The first time the day happens, Paige is quickly identified as the victim of a drug overdose. However, we find out later that she actually died by violent strangulation. Yet the only sign of trauma on the corpse was minor hemorrhaging in her eye. There should have been obvious signs of the confrontation, starting with huge bruises on her neck.
Plot hole: Why hasn't Tru met Luc? He came to the morgue very late the first time the night happened in the previous episode, after Marco scared Tru. Even though Tru seemed to stay at the bachelor party very late the second time the day played through, she had gotten into work by the time Marco tried to scare her again, so she should have still been there when Luc came in.
Chosen answer: The next episode shows that Tru didn't meet Luc after all, even though she should have been in work by the time he showed up. I think the answer is that the writers don't actually know.
DavidK93