Stuff like this is why I wish you could review the companies code before joining. Getting hired, discovering how bad everything is and then starting the job hunt again is awful for everyone.
In one particular instance I came back to review the code for a product that required a level 3 security clearance; the hiring manager happily complied, letting me spend over 2 hours alone studying the code on a workstation in a side office. One reason I passed on that position was due to the code being more spaghetti than I would have preferred.
I usually meet with the team on a casual event outside the office before accepting any offer. I find that its a very good way to find out about the team dynamics. A lot of warning signs about management can be easily spotted within half an hour of talking to them.
A big warning sign is usually high turnover.
Post interview I'll talk to the hiring manager and express how much I enjoyed meeting with the team and love the product, then ask if it would be alright to stop by to take a closer look at the codebase, watch how the team works in action, just be a fly on the wall.