Hydra shocks probably would not have mattered, and yes, you are missing the point.
There is NO magic bullet...(certainly not outdated designs like HS)
The Hydrashock would make a slightly bigger hole assuming it didn't plug, but there is NO reason to believe it would have penetrated as far...and certainly no farther.
John used to tell funny stories about people that had been shot multiple times and they fell down due to "graying out " blood loss.
Only to get back up when the blood ran back to their brain while they were horizontal
The lesson is....plan on making multiple well placed shots
And don't stand there looking surprised when the BG doesn't just fall down and die
Caliber is much LESS important than placement and frequency
What would have stopped her laughing would have been more torso hits!