If the vehicle has moved in this turn, then I think Klas' q&a would rule.
Could be...Or the two Q&As could describe a difference between abandonment and survival. "Abandonment" equaling a form of movement into the Location and "Survival" being a continuation of the already existing, vehicle-vs-infantry Melee.
I agree that there should be a Q&A asking if there really should be a difference - otherwise, these Q&As appear contradict in this situation. The relevant passages in the RB seem to be these:
A11.15 MELEE: If Infantry of both sides remain in the same Location after all initial CC attacks have been resolved at the end of a CCPh, they [EXC: bicyclists, skiers] are considered to be locked in Melee and may not leave that Location or attack except as part of CC.15 Infantry are also held in Melee by enemy Cavalry, cyclists, and non-Abandoned, Stopped, "unbroken" (12.1) vehicles.
A11.71 OTHER WITHDRAWAL FROM CC: Passengers/Riders of Immobile vehicles are held in Melee, but Cavalry, cyclists, skiers, and Passengers/Riders of Mobile vehicles who survive their initial round of CC are not required to remain in Melee. These units may dismount during their next MPh and remain in Melee without their prior handicap, as may Passengers/Riders of Immobile vehicles, or they may move out of the Melee Location in their mounted mode normally during their next MPh. Should they dismount, their form of conveyance remains with them and is subject to capture [EXC: A Mobile vehicle can still move out of the Melee Location and a manned AFV is never subject to capture]. Whenever any of the ATTACKER's units leave a Melee Location, he must declare whether any units will remain behind to preserve the Melee. Should no friendly units remain behind to keep the enemy in Melee, those enemy units are freed from Melee and may Defensive First Fire on the moving units.
and maybe:
A3.8 CLOSE COMBAT PHASE (CCPh): Units of both sides occupying the same Location resolve their CC attacks; any survivors which have not withdrawn are considered in Melee. The ATTACKER places a "?" counter on any of his eligible unconcealed units as per 12.12-.122. Remove all TI/Pin counters. Flip CC counters over to Melee side or remove them.
One question I have is whether the Melee still exists at the instant the vehicle is abandoned. It seems to me that the correct ruling should be Klas's Q&A regardless of whether the crew "survives" a wreck or abandons the vehicle - since Melee would be briefly over when the vehicle is destroyed/left. However, where in the RB does it state (besides A3.8) the moment when Melee counters should be removed?