It's a rare bug, but occasionally after the death from above nuke the HUD won't reappear. The only solution was to exit and reload a save. It only seems to happen during missions.
Huh, interesting. For some reason this reminds me of when the camera would disconnect from the player after certain actions in Saints Row the Third. The only way to fix it was to reload a save. I've personally never suffered from this missing HUD issue, but you can add a cheat that can disable your HUD or re-enable it. It might help you bypass this issue for the time being. IdolNinja has this set up already with his Additional Cheats mod.Second that, seems to happen pretty often for me, and outside of missions as well. Not only is the hud missing, I can no longer move or change weapons, only aim and fire the current weapon.