Why the George Cross (and not the Victoria Cross) for an active member of the UK military (WWII)?

As evidenced by his uniform in the picture in the Wiki article on him, the indomitable Forest F.E. Yeo-Thomas was a commander in the British military (RAF) at that the time he parachuted into occupied France in 1943.

Given his active military status, then, why did he receive the George Cross (the civilian award for supreme bravery) and not the Victoria Cross?

From Wiki

Bolding is mine.

The Wikipedia article you linked to linked to the one on the George Cross, and this article said, “The GC is the civilian counterpart of the Victoria Cross (VC) and the highest gallantry award for civilians as well as for military personnel in actions which are not in the face of the enemy or for which purely military honours would not normally be granted.” So it’s probably because of the bit about actions which are not in the face of the enemy.

Yes, but IMO he was most definitely in the face of the enemy (while being tortured, for example, for the withstanding of which he won the award).

That being said, you are probably correct (insofar as the official reason must be that “face of the enemy” refers to battlefields and the like, and not concentration camps)

One distinguishing characteristic of “actions which are not in the face of the enemy or for which purely military honours would not normally be granted” would be that they cover situations where the soldier/sailor/airman would not be wearing uniform. While Wing Commander Yeo-Thomas was in occupied France, he would not have been wearing his RAF uniform (and so would not be entitled to be treated as a POW if caught).