The Vortigaunt killed Frohman because he knew too much.Why did the vortigaunt leave Frohman to die in the end of the series? Because he shoot them? They are not petty enough for that, besides, they saved Freeman, who has already killed who knows how many of them. Because he is a moron? No, we already know that Freeman himself is not much better. The obvious conclusion is the vortigaunt have been plotting the downfall of the human race all along, and Frohman knew it. But, did they merely leave him to die? In Half-Life, people dont die when they have one point left, no matter what kind of amusing injuries left them in that state. No doubt it was the work of the vortigaunt. They have been plotting the death of Frohman for long, but in every ocasion there was some nearby humans and they had to keep appearances, even ocasionally saving his life, ironically enough.
Concerned is canon in the Half-Life universe.Hence, the Playstation Half-Life is non-canon. It will probably be alluded to in Episode 3.
Concerned is in the same universe as Civil Protection.
The Vortigaunt left Frohman to die because they were aware he caused a lot of trouble
Gordon Frohman briefly worked for Aperture Science