Everyone got power back when the first ship left. The power loss is part of the scripted event sequence, so it makes sense that the loss goes away at the point where the ship starts to leave.
Note the second ship trying to get into position and not being able to due to the first ship being there. The collision detetection prevented the second ship feeding/refuelling/whatever until after the first ship buggered off.
I like buggy instances because they give you a look under the hood that you wouldn't otherwise get.
Ah yes, that makes sense! Thanks