Snip
(Also never seen the enemy affected by it.)
I can count on one hand the number of times an enemy has moved into a position to do so without being a melee enemy. The AI retreat conditions(x number of enemy currently spotted) is usually met well before 1 square distance unless the player is intentionally provoking the occurrence, like when "stacking a door".
Right now while the CQC check may be a universal rule, the AI is generally prevented from arriving in the situation by superseding conditionals.
This can be used to the player advantage is some situations, mostly dealing with tank style terror units. If you can catch such units that don't have melee skill in a confined space you can pin them with a decent melee gal who can then take all the time they want killing it, cause it can't pass the CQC check. Don't try it with cannon tanks though point blank aoe not fun.