OK, just did some quick testing with poor quality crews.
If the tank crew bails on player command, the AFV is treated like normal enemy unit.
If it bails under fire or is knocked out, you can't target it.
I remember that is what I did to the AI in one game. My crew bailed of an immobilized tank with a crew casualty. 15 minutes later, I re-entered it and shot up a couple HQ units.
To get the bail out, I set up a bunch of poor quality T-55's and shot at them with a warrior. Eventually, enough damage is caused to bail.