While this is factual, it's lazy to blame West Ham now, rather than highlighting the fact that we got ourselves into that position by way of being utterly dreadful for much of that season.
For example, we were relegated by a single goal. We missed 3(?) penalties that season that I remember, 2 of which were in the same game.
If Warnock hadn't handled Villa away so horrifically, we would have stayed up.
If we hadn't gone to Arsenal/Chelsea/Spurs, and just taken the beating, we might have gotten a better result and stayed up.
If we had recruited players who would actually play, and not the likes of David Sommeil, Chris Lucketti, Mamadou Seck and Li Tie, we might have had a stronger squad and survived.
Also, if we look at the presence of Tevez in particular (Mascherano was not particularly influential for West Ham), we can look at the fact that they had a goal given to them away at Blackburn that A) Didn't go in; and B) Struck Tevez who was offside on the goalline. That should have been ruled out, which would have made that game a draw, and then we stay up.
We were in a relegation battle regardless of West Ham's actions that season. And there were many, many things within our control, that would have seen us stay up that year if we'd taken those actions, beyond just the things I've listed above. And we failed to do so.