Does Command Undead Survive Death? [Mild Dead Suns Spoilers]

Hey everyone, I just had one of my best gaming moments in my weekly starfinder game, but now I have a question.

​

Without spoiling too much, towards the end of book two of Dead Suns there is an intelligent undead that has been unwillingly told to stop the party through the spell command undead. He told us as much and asked that we stay away so he didn't have to kill us, and my mystic was able to ascertain that he was under the effects of that spell. So he did a ghost sound of an approaching group of people and suggested with a big wink to the undead elf that he stop those guys from entering while we 'promised to stay right her,' allowing the elf to use a loophole to regain a little bit of his lost agency. He left and we moved on. It was awesome and a ton of fun.

​

Now I understand that this may or may not be technically allowed by the rules, but my GM loved the idea and let us roll with it, so what's done is done there. Afterwards, I asked my GM if my character would know if the spell ended once we killed the bad guy. He honestly doesn't know (we're all relatively new to the system, but came from Pathfinder so we've got the basics) and gave me homework to find out.

​

So.... does it? Thanks in advance!