I agree with GM1 about Bobby from Shaka Zulu probably forcing the doors open with his hands. If you watch the run, you can hear a thud noise and the door doesn't open naturally. It wouldn't be unusual for him to get it open since the doors have been opened in the past, both by contestants and by themselves. The same thing happened to Billy in Lost Hammer where he tried to force the golden doors open with his bare hands. Whether Bobby cheated or not though, I think we can all agree that this was not the intended path to the artifact.
Personally, I blame the producers for this.
The passageways from the swamp area never had any physical doors (like the Pit,Ledges, Shrine and virtually every other room).
So, the intentions were that if a contestant were to go through the doors they would be stopped by the second set of doors leading into the next room. The bottom room of the center shaft, had that big golden door that would be locked unless the task unlocked it.
The golden doors room, however, at least in early Season 1, could be opened and closed manually, this was fixed in S2 as Shane from the Turban episode clearly doesn’t press an actuator from the swamp, but has to go back to press it.
Additionally, the golden doors rooms were often left ajar, so my guess is he tried to press the actuator, went through and manually pushed the door open, which again, in Season 1, was often required. How many times did a contestant have to “slide open the door” from the Pit to the Observatory, or open up the door from the Throne Room to the Swamp? In later seasons when doors opened they usually had more force in them so a contestant could clearly see that it’s opened.