Never take a fish above 5000 feet in altitude. EVERYONE knows that.
Most likely this was a low level route and the aircraft never came close to 5000 feet. I flew on hundreds of these missions as a C-130 loadmaster. Even though this was a C-17 jump, the cabin altitude would never have been above 5000 feet.
If the bottle was sealed - no problem. The guy’s not going to jump from 30,000 feet. Look what he’s wearing.
You apparently have never heard of the area immediately surrounding the Continental Divide, or the MANY fish living quite happily there at altitudes over 12,000 feet.
....or maybe even those at higher elevations i.e. the Andes or Himalayas.
(Just gotta watch that "always" and "never" deal, doncha?)