I'm not sure if this explains the scenario you saw but this is how I understand it:
Basically, say Phil is a 95% favourite, and the pot is $100k, he will offer to pay someone $5k so that the hand will hold up. However, if he loses the hand then they owe him $95k.
Either way, in theory he gets the $95k for his hand and avoids a bad beat regardless if he wins or loses. Nevertheless, the players might not always insure for the full amount or for the exact odds
of the hand and it will probably work out as -EV for Phil if someone does offer to insure the hand.
There are a lot of high stakes poker videos on YouTube. Maybe if you post an example of one you are confused about then someone else could help explain better?