Other mistake: The security guard alerts Batman about Barry Allen's arrival pushing a button on his phone. The date on the phone says it's Friday 20th Jan, which is coherent with the year (2017) this version of the movie is set in, but too early for the K-pop "As if it's your last" music video playing in Flash's lair (it was a summer release). (00:16:50)
Other mistake: The janitor, Howard, stops Dr. Stone to talk to him about the loss of his son. Look at his badge; the person on it sports a beard and sideburns and a hat, and it's "Jensen" plus initial. Later on the same janitor hears a noise inside the lab and you can see the badge picture is different and it lists the full first and last name. The first scene was a Whedon reshoot, so probably after weeks they didn't have the original prop and made another one. (00:18:55 - 00:21:15)
Answer: Bruce Wayne is not only rich and powerful, he's also dangerously vindictive. If you cross him or his friends, he'll pull the rug out from under you, at best, and destroy you, at worst. At the end of "Batman vs Superman," Bruce Wayne realises how horribly wrong he was about Superman; he even feels a kinship because both of their mothers were named Martha, and he was finally able to "save Martha" (something that had haunted Bruce Wayne for his entire life). I'm thinking, once Bruce Wayne discovered that Martha Kent's house was foreclosed, he acted to not merely save the farm but to punish the bank that foreclosed it. So he bought the bank and probably ruined a few financial careers in the process, out of sheer vengeance.
Charles Austin Miller