Hahah that's crazy. The craziest bite I've ever seen on video was by Bad Rosemary. Left a big hole on the chest. Now that's a freak mouth.

To update my pup; he decided to finally hold on to the hide (2nd day ever springpoling w/ a cow hide) albeit for only 50 seconds (he was only holding on for like 2-3 seconds the first day). I think this confirms what you're saying EWO that a dog bites hard when it wants + how bad he likes the toy/hates the dog.