EVZ,
I agree that if the Do335 had been on a combat mission and encountered four Tempest Mk Vs the best thing for it to do would have been to run.
Now, what do you think would have happened with this Do335 had it encountered a C-47 Skytrain or L-4 Grasshopper? This is where we run into a problem considering that encounter with the Tempests to have been combat, the Do335's reaction to run needs to have been a calculated one based on the number of hostile fighters, not the default action of an unarmed prototype on an evaluation flight.
There was no chance of that Do335 doing anything remotely aggressive, even against a single, unarmed Allied aircraft.