It's all about match ups with Isaac. When he doesn't have a someone with size to go up against, he can struggle on both ends and I think he gets frustrated trying to get a feel for what he can and can't do.
That being said, the fact of the matter is he's often significantly larger than other players he's up against. So his sheer size and strength can basically manhandle people, which gives the appearance of a foul. Not saying it's right or wrong, but I don't think in every instance the refs are doing a bad job.
NW doubled him and Swanigan when they got the ball - Swanigan got his points, but wasn't overly efficient in doing so. They both need to do a better job of being more decisive (some of Swanigan's plays remind me of Hammons - way too slow to develop and it basically telegraphs what you're going to do). NW was also pretty effective against Haas in the first game as well.
There's a good chance in both tournaments we'll play against a team that doesn't match-up with a traditional center. Having the size of Haas can be a great thing, but it can also put you in a bad spot if not utilized effectively (which isn't necessarily the fault of player or coach - sometimes others teams are just good at preventing it, like NW was for 2 games).
I think you're also going to see Swanigan doubled in almost every game from here on out. Swanigan has struggled in those situations, so we just need to be smart with the ball and keep turnovers low, and continue doing a great job of finding open teammates who have shown to be effective with the ball.