It's not hard to believe in a Steven Jackson injury; it is a little hard to believe that Steven Jackson, a little injured, would stick around in pads on the sideline without trying to get himself back into a 31-28 game in the final minutes, when backup Daryl Richardson's fumble almost cost the St. Louis Rams their first win of the season. Enter the Steven Jackson benching rumors. Jeff Fisher's going to have a hard time convincing a certain subset of Rams fans Jackson wasn't benched, no matter what he says.
And there's a vaguely reasonable ground for questioning it; Jackson just didn't look, to everyone watching in-stadium and on TV, like they imagined he would if he were injured in a close game. I have no particular reason to personally disbelieve Jeff Fisher's explanation--that Jackson injured his groin and missed every Rams drive after his unsportsmanlike conduct penalty.
But I'm not the kind of person he'd have to convince. The explanation that he was benched as a lesson that no one player is bigger than the team is going to maintain a lot of currency with people, and I'm not sure there's any way around that.