Why did only 2 of 3 tourists itinerary get met?

[Uberubert]

1 rocket, 1 launch, 3 tourist.

All 3 tourists require "Suborbital spaceflight on Kerbin" and nothing else.
All 3 tourists were part of the one rocket on the same launch to the same height (75Km).
1 Tourist stuffed into a KV-1 "Onion", and the other two in a KV-2 "Pea".
Two of the tourists got the green checkbox. The third one did not. (Not sure which were seated where)
All 3 tourists returned safely, I got paid for two of them and one of them still needs to go suborbital.

Am I missing something or did I encounter a bug?

Playing with 1.6.1.2401 (WindowsPlayer x64)
1.6.1 Making History
1 mod: TAC life support.

[StrandedonEarth]

All I can suggest is to read the contract carefully. It may have said “suborbital on the Mun,” or it may have a requirement for a pilot to be along, or some other unexpected condition. But if you’re sure you’ve met all the conditions, and you think it should have completed, then you could force it to complete in the cheat menu