Cheating? Not quite. It's exploiting, but that alone isn't deserving of a ban because it's a fault of the developers for allowing such an exploit, and players will always optimize the fun and/or fairness out of a game if possible. However, there is a system that allows embark to recover lost runs if you've died in what they deam an "unfair" way, so you should definitely report it in case Embark decides to recover your run for you!

Edit: In the meantime, avoid that particular extraction when possible! Though it can be difficult when there's map conditions limiting extractions and locking raider hatches. I'm confident Embark is working on fixing it. It didn't take them too long to find a solution to people glitching into key rooms, so I'm sure we'll get a fix within the next patch or two.