should I address an employment gap and a short tenure on the resume?

Hi keendemo - what kind of accident? If it's an auto accident where you were not at fault that is one thing, if you instigated a barroom brawl that would be a story best avoided.

Regarding the previous job, does it span across 2 years? Remove months off your resume and make it like 2016-2017. Honestly the school cares but more so in terms of how it looks to recruiters. I will say, people in tech change jobs frequently at least in Silicon Valley, so my understanding. That might mitigate things.

I do think I would address it, email them and hopefully they can include that in your file. You might also include something about how in the future you will do more research into the product before taking an offer? I mean not blaming you but it is always attractive to see someone think about their role in things and demonstrate personal awareness.

Finally, wow surprises me there is no reason for leaving section, that is very odd. I believe you but just saying, very odd. Write your email and ideally have an admissions consultant review it, if you don't have one, have a couple people review it who are a bit "outside" the situation and can give you outside perspective.

Best of luck!