I've been attempting a 1-crew run for a few days now. I was on a roll, when suddenly my Engi died for no apparent reason. This is the second time this happened since attempting this run, the first time while also having a good run.

Screenshot: http://imgur.com/vHAo4JG

Going into the battle my Engi was at full health and my ship had 0 damage. Everything was powered.

It wasn't suffocation. The med-bay, cockpit, and hallway between them were sealed and the oxygen was running.

I didn't get hit. My shields were at full and my hull is still full. He fired the smaller missile (Artemis?) but I cloaked through it.

The only possibility I can think of is I was boarded and didn't notice. But I have always noticed this before, and I don't see the warning or any indication on his teleporter that he just beamed anyone over.

Is this a bug?

Hugely frustrating, getting through the first few sectors with 1 crew and this ship is tough unless you get a lucky drop. I got the Ion Blast II early in the third sector and it was a lot easier from there. The strange thing on this run was at no point did I encounter a store selling drones, and the only drones dropped for me were more Personnel Drones. (I swear, I must have had a dozen of those drop.)