This is the actual red flag. A mid-size firm simply couldn't function without IT. They could outsource it to a contractor, but, in that case, they'd never then hire someone for 90k to do one small IT task.
If there is any true to this, he's probably on the books as an "Litigation Support Tech" and his job probably involves (or is supposed to involve) more than he's describing--like interfacing with vendors who do the actual data/document processing.
My point was that they may not even be big enough for one. “Plug and play” might be good enough for now (a shared drive means someone is around though, someone had to set it up).
There are definitely small firms that rely on the young paralegal who is a self taught super user. But that sort of firm wouldn't pay someone 90k for doing a small part of all IT.
Slight chance this person was hired as a "case assistant" or "litigation support" and not IT. Firms definitely hire that sort of person--though they usually bill their time--so hopefully the OP isn't submitting fraudulent time entries. But 90k is a lot for that sort of role without expectation that you are performing other tasks.
I’m still skeptical. I was hired at ridiculous rates once ($2k an hour) to validate DKIM signatures by a small time firm. 90k to be “on call” and validate things seems totally reasonable even from a small firm.