Well he should not of thrown up over his student. Everyone knows that if you do need to yawn in motion its either a stop and swallow or down the side in a bag out of view.
Then bull**** some crap about why you are "unwell" . Dont worry the student will be so far up their ass thinking about what glories are coming next that it would barely raise am eyebrow. And if it did you'd smack it down quick hard and spray stale piss in their face as you belch "what the Fark is wrong with you?"
Easy enough to wallow an aircraft round the circuit a bit on the nose especially if the student has double digit hours you're really along for the ride so just sit back and think about your recovery methods that night like why did you scare that nice young blonde off from the bar so quick was it my plastic personality? Dam if she was a student I could of stiched her up right there and then.