I addressed that issues years ago on another board. It actually makes perfect sense. The gist of it:
When you're the only guard left standing in the theater defending your ship from deadly attack, you already have your prisoner for interrogation, and you're being attacked with weapons that probably don't even need a direct hit to kill or least incapacitate you, then you increase your setting to the maximum possible to give yourself your best chance of accomplishing your duties. The intruders boarded willing to kill to accomplish their mission, they did kill, and they were loose. They had to be stopped. Fuck that kid gloves bullshit.