DevOps is a culture but many companies just follow suite and put up a team called "DevOps" without getting into the heart of it.
I think there are a few questions you can ask, but in general there are only two that matter:
1- Does upper management support the team, or, does the company have good engineering culture?
2- Does the team lead have good knowledge, or, does the team gather requirements and other info before pushing out their "DevOps" projects?
BTW I have been thinking about engineering culture. Sometimes people think that a good culture just means a blank cheque, but I think it has to be good on both sides. Upper management should give some freedom but engineering team should also gather enough info and evaluates projects before execution. Sounds like common sense but ask yourself or your neighboring teams: Do you always gather enough info and validate your projects? Have you ever volunteerily turned down a proposal without fear?