Maybe the service did a terrible job. Still, it would have to be very bad for me not to leave at least 15%. I try to leave at least 25% if the service is good. Especially if it's a place I've went to often. These are people serving you food, many of whom make below minimum wage (or some only tips), which means the food is priced lower than it could/should be anyway. Unless they've went clearly out of their way to be rude to you, tip them. And no, forgetting to check up on your table when it's busy isn't necessarily rude, or screwing up your order isn't necessarily rude, could just be a miscommunication with the chef.
It's nice to hear nothing but great things about Lemieux. Especially since he's a pretty private person, he handles fans exceptionally well.