Not 100% sure so don't be quoting me on this but I think they can lift the vehicle if somebody is in it but they can't tow the vehicle with somebody in it. Also if it were a repo (not saying this one was a repo) and the tow truck driver has lifted it and calls it in, it is considered grand theft auto for jumping in and driving off. Again I'm not 100% on that as I can't remember for sure.
I was actually looking into running a wrecker service and had talked to some people about repos but don't remember for sure on everything. Seems like I remember this stuff though. But I very well could be wrong and it may also depend on the state.