> stealing from your former employer would get you fired immediately
Since that would pretty much be an admission of guilt, you leave out an important detail here. This will only happen if your new employer both believes you did it, and that they will lose the case and get an unacceptable penalty imposed on them as a result.
If they intend to defend themselves, the behavior would be reversed : Legal would strongly object to your firing (or quitting) until the case is over, including all appeals and the terms for any further appeals are over and done with.