Play Ball - August 6, 1961 - S4-E2
Continuity mistake: The mud stain Sam gets in his slide covers most of the front of his baseball jersey. But a few shots later, it becomes a much smaller streak on just the left side. (00:06:30)
Continuity mistake: In the scene in the courtroom, when Kevin is being questioned by the prosecutor, she introduces several photos of Katie to the judge. The judge keeps two or three of them, and the prosecutor carries one to the witness stand. As she is carrying it to the stand, it can be seen that it is a photo of Katie wearing a dark top, with what appears to be a fluorescent light over Katie's head. The prosecutor then places the photo on the stand for Kevin to view, and it shows Katie wearing a white hospital gown with blue dots. After the prosecutor questions Kevin, the defense attorney walks over to the stand and picks up the photo. This time, it shows Katie in a red v-neck top, with no light above Katie's head. (00:30:35)
It's A Wonderful Leap - May 10, 1958 - S4-E18
Continuity mistake: When Sam goes in to talk with Max's father, Sam/Max is wearing glasses. But in one brief shot, his reflection in the mirror isn't. (00:20:05)
The Curse of Ptah-Hotep - March 2, 1957 - S4-E20
Continuity mistake: When he starts swinging the pick-ax, Sam's bandanna instantly moves between shots from around his neck to over his face. (00:19:25)
The Curse of Ptah-Hotep - March 2, 1957 - S4-E20
Continuity mistake: The size and shape of the hole Sam creates, when he breaks through the wall, is considerably different on the outside than it is on the inside of the burial chamber. (00:20:10)
Answer: Sam threw items off the raft to lighten the load, so it wouldn't sink, in doing so he made the raft less heavy. Which made easier to float with the currents, if it was heavy the raft would have moved slower and not moved so far.
Except that Al said that immediately after throwing stuff out of the boat four hours passed and it was shown that they didn't really move from where they were. They were still in the same spot. Forgot to ask this too. When Sam and Vanessa are stranded on the island, one of them, can't remember who, did something and when Al appears, he tells them that because of it, time had suddenly skipped several more hours and if the event hadn't been interrupted, they would have been rescued by a boat. So, what happened on the island that once again caused time to speed up? It seems kind of strange that time could move so quickly on the island, especially since it was still day time and it never showed any sort of changes like the sun or clouds moving.