S.T.A.L.K.E.R. (bad news?)

This is not yet to take too seriously, but a bit worrying anyway: according to Shacknews , the development team GSC would have been using software material from Half-Life 2 and Doom 3 ,without permission, to produce STALKER. Both Valve and ID software have been contacted and at the time, only ID has cautiously reacted. Not a word yet from Valve.
The pic above will show you a water texture comparison between HL2 and Stalker. Once again, this is all to take very cautiously, as CryTek (Far Cry) has been accused in the past too, and it turned out that everything was bullshit. More to read in this thread.