I am confused by this story and your statements. You claim metagaming is so horrible that you will not do it, but you expect the DM to wave his hands and get you back into the game after you make a bad decision. It seems like you are complaining about not being able to have your cake and eat it too. What am I not getting here?
Then I'll attempt to clear up the confusion. Bad decision or not, it's the GM's responsibility to keep the game moving, and keep players involved. There's no way, in any of the myriad aproaches to GM'ing, where leaving a player sitting with nothing to do for over three hours is a good thing to do.
The decision to stay and guard the spacecraft was not taken as a completely arbitrary decision. I and the group (but mostly me) asked the GM questions after we arrived at our landing sight. Questions such as; "Is there any way to secure our spacecraft?" - answer "No", "Would guarding the spacecraft be a good idea?" - answer "Do whatever you feel you need to do." So, it was decided that the spacecraft needed to be guarded. There was the worry that we may not necessarily be on a "friendly" planet, or that the Empire may have followed us.
None of us in the group realized that the GM had an extensive tomb/dungeon encounter planned. When it became obvious that this wasn't going to be a quick encounter (after twiddling my thumbs for the first hour). I tried to get the GM to help me out with a reason why my character would leave off from his "duty" of guarding the ship, and even gave him ideas or "outs", but he refused all of them.
At any time the GM could have said that there was no reason to guard the spacecraft, or could have said my character was getting a feeling of unease through the force that my friends needed help, none of which is "hand waving", but is actually good GM'ing. Having a player sitting with nothing to do for three hours, and not doing anything to get the player involved, and actually actively shooting down ideas from that player that could get the player involved, is nothing short of horrible GM'ing.
After being left out of the game for over three hours, and then having my character killed with no saving throw, defence roll, or anything, I'd had enough.
I don't feel asking the GM for help was outside of the concept of the game. While GM's should try and avoid GM fiat as much as possible, there are times where it becomes necessary to keep the game going and the players involved. Conversely there is no such thing as Player fiat, it's the GM's world and rules, not the other way around. The only option other than GM help, was for me to say "I'm tired of guarding this ship (something a Jedi wouldn't do) and since I'm bored and want something to do, I'm going to go down in this tomb (of which my character had no knowledge that there was anything untoward, or that there even was a tomb) and go have some fun." all of which was outside of character knowledge. All I did was give the GM ideas for getting my character involved, ideas that he should have already had, and he shot every one of them down. To this day I still don't know if it was incompetence, ignorance, or just spite, but it was the end of my gaming with this group.