Allow me to jump in and suggest that you don't even need a lapse, per se, in training for it to be dangerous. I used to know a fellow who worked with mountain lions, and we got to talking on occasion. Anyway, for all intents and purposes, these cats were basically tame, he said - they were mostly born and raised in captivity, and were quite comfortable around people, sort of like a big housecat. But, he said, he never dared drop his guard when he was around them, particularly when they were acting like big housecats. The reason for that wasn't that he was afraid that they'd actually attack him with the intention of doing him harm. Rather, the reason was that they were such immensely powerful animals that one swipe was quite capable of snapping his neck, even as a matter of play. They wouldn't intend to harm him, but their strength was such that even playtime was potentially dangerous to humans. Given that, I hesitate to imagine a "pet" bear in a playful mood.
Ask Roy.
That's what Roy Horn says, but I don't buy it. The tiger that mauled him wasn't "playing", but reverting to type. "Montecore vuz tryingk to save me!" Yeah, sure...save him for breakfast, perhaps.
The reason for that wasn't that he was afraid that they'd actually attack him with the intention of doing him harm. Rather, the reason was that they were such immensely powerful animals that one swipe was quite capable of snapping his neck, even as a matter of play.
Horses and cows are stronger still. Potentially dangerous, yes, but we trust their temperament in situations where we could never trust a trained wild animal.
Given that, I hesitate to imagine a "pet" bear in a playful mood.
I don't imagine that domestic grizzlies would be used as lap animals. I imagine them loping around a car dealer's lot at night, or pushing concrete barricades into place, or running down a perp.