Here is another clip of someone getting the boba fett jetpack glitch. This video was made after the Grievous update
https://www.twitch.tv/videos/331423761
Apparently this player was not able to get his jetpack started again. I don't see any good reason why this happened here.
I've noticed that jetpacks are more glitchy when they are used just after you jump (Especially the jumptrooper of the clankers have often not-starting-jetpack on jumping). However I am not sure that this causes the Boba Fett jetpack bug.