" I didn't see what happened, if the other dog did something "
Anything besides suggesting that you supervise all other occasions would be guessing.
IMO, young intact males may have a faster trigger due to the testosterone. (May become more easily aroused during play) which with constant supervision from you could be defused before anything escalates.
I think it all has to deal with training. He needs to learn what is acceptable when he is having testosterone surges and that can only happen under your guidance.
Anything besides suggesting that you supervise all other occasions would be guessing.
IMO, young intact males may have a faster trigger due to the testosterone. (May become more easily aroused during play) which with constant supervision from you could be defused before anything escalates.
I think it all has to deal with training. He needs to learn what is acceptable when he is having testosterone surges and that can only happen under your guidance.