Exercising sound judgement is the most important riding skill. Everyone makes mistakes though and I wouldn't judge a person on one mistake. If all three accidents was this same buddy, sorry, he's a bad rider. There's enough things that can bite you when you're being careful, most having four wheels, that there's no point in getting a little crazy. Particularly up north at the start of the season. It's easy to forget just how much of your concentration riding a motorcycle demands. It's easy to get caught up in passing and let slide judging just how sharp that curve ahead might be.