Yep that sounds like it. I just managed to miss part 2. Drat! I do seem to remember some followup news coverage that indicated it was likely the hatch blew by itself, just as Grissom had said.
As I recall this WAS a two part program. They had the chopper pilot, who was sent to recover the capsule and Grissom, on board of the recovery ship. They brought the capsule upon the rolling deck of the recovery ship and then had an EOD team try to disarm the explosive escape hatch devices located in the capsule. The show ended with the Liberty Bell sitting on a flat bed trailer and an interview with Gus Grissom brother. Seen the program a couple times. Excellent underwater footage. I was surprised to see the capsule in almost perfect condition for the amount of time it spent in seawater.