aleeque: and since this was the first enemy met by me, if he chose to radio his allies, they could've used either of the detonators. But he didn't, he just shot at me until he died. I guess the AI won't use the radio if they have more important things to do, like fighting back?
When Enemy in direct contact with opponent merc, he could decide only from fight or flight (more precisely, unless that enemy already on the move to sabotage target, in this case he will ignore everything else as long as some path to it is open). Fight or flight decision is based on expected damage could be done, and by Orders and Attitude of Enemy in question. When Enemy do know about opponent merc's presence, but not in direct contact with any of them, he could do some other thing, like radio to other enemies. Thats why they do that odd maneuvre of running away from player sometimes: to be able to do some other options like radio, instead of immediately engage in battle. In any case, the chance for radio is random-based, and enemy could decide to not do so, sabotage missions do not affect it. That mean what directly engaged in fight Enemy could eventually decide to take a cover and, due to losing a direct contact with player's merc, proceed to another option, like radio; but generally "engaging in battle" works for player well, just without 100% guarantee (of course enemies around could also be awared, say by hearing a shots).