Revealing mistake: There are noticeable differences in the appearance/condition of the lattice panels on the deck (overlapping; whether there are missing/broken slats and, if so, their locations), but pinpointing most of the differences would require pausing. When Thomas was seated in front of the panel adjacent to the door, sometimes there were broken/missing slats but other times they were intact. Most revealing was the absence of the lattice panel opposite the front door when Liz was standing near Thomas. (00:42:17 - 00:49:42)
Continuity mistake: At various points throughout the movie, the position of the lamp on the end table (to Charlie's left where he usually sits on the couch) changes, from the base being in the back corner, to mid-way along the chair's arm, to being centered along the rear edge, to near the middle of the table, etc. As the lamp's position changes, the other objects on the table also change. (00:02:15 - 00:04:21)
Suggested correction: "At various points throughout the movie" so he moved his lamp. If the shots aren't consecutive (screenshot, please) this is not a continuity error.
Plot hole: Other than being an on-line college instructor who "works a lot", the status of Charlie's employment was not revealed. There's a big difference between being a full-time tenure-track instructor (with a fringe benefits package that would include health insurance) versus part-time/adjunct faculty (with low pay per course and little or no benefits). Charlie was able to save $120K in 8 years, suggesting he was full-time and should have had health as well as life insurance and a retirement plan.
Suggested correction: Not necessarily. My uncle works as a college professor (typically part-time or single-semester gigs) and has been able to set aside pretty good money by controlling his spending. Granted, not $120K... but my uncle also spends more money than Charlie on leisure things. (Also, according to a quick Google search, a part-time college professor often makes as much as $40K+ per year depending on different factors... pretty easy to save money if all you're spending is rent and food).
Plot hole: After sending the offensive message to his students, Charlie got on-line with them (within hours or the same day?) and said, "Well, your complaints have been heard. I've been replaced..." IF an on-line college instructor could be terminated and replaced as quickly as Charlie was, it would follow that he would no longer be able to access the on-line course to communicate with the students like he did. (01:39:55)
Suggested correction: I think this is based on too much assumption. Any sort-of ban would likely be entire dependent on whatever system they're using for their online class. And it's entirely plausible he'd still be able to access his account mere hours later, even if the call has already been made to replace him.
I worked for the Defence department in Australia and it was a running gag that eighteen months after I had left my online access to my account was still open, allowing me access to highly classified documentation, including emails. Mistakes happen.
