Not necessarily. His description of how fast the boat sank sounded like a more catastrophic failure than a blown seal, and water coming in that fast may have overwhelmed a bilge pump even if it was working perfectly.
I'm reminded of the Scubamau boat that sank 5 or 6 years ago crossing the channel. It was a former glassbottom boat modified to a dive boat and sufffered sudden and catastrophic hull failure, going down in seconds.