The Robinsons Were Here - S1-E4
Stupidity: Satellite dish falls, trapping people inside, and they can't even figure out a basic thing like digging a hole to escape. (00:43:52)
Suggested correction: I didn't see anything they could use to dig their way out. Plus Don was on the other side, so they knew they could just wait.
Infestation - S1-E3
Stupidity: So "Dr. Smith" runs into her sister's boyfriend on the Resolute and pushes him into an airlock when he figures out who she is. The door immediately closes and a countdown to purge the airlock ensues. Who would design an airlock to do that? What if someone went in there by mistake or was doing some maintenance on it? To make it worse, there's no override inside the airlock? It's located in the corridor.