Never got this. If Hauk was not planning on telling Snake about the capsules, then what was stopping Snake from getting POTUS back in 22 hours? I mean, if Snake didn't know about the capsules, what would be stopping him from saying "fuck it" and taking the glider to Canada?
Maybe the OP thought Hauk had been planning to keep it secret until the med tech said, "Tell him!"
Personally, I suspect Hauk was just waiting until he was out of grappling range before telling Snake himself. Maybe even waiting until Snake was already in the glider.
Sort of like the sequel, where they purposely load his first clip with blanks.