Well he wasn't very special in his draft eligible season (2010) as he put up only 19 points in 70 games, and he was passed over in the draft. His following season was really impressive (81 points in 64 GP) but it still only got him drafted in the 5th round, so there must be something about his game that made scouts worry about whether his skills would translate. Now he is also playing his 5th season in the WHL rather than getting signed and moving on to the AHL, so again the Isles must recognize that this guy is going to take some time to get there.
With Reinhart, Donovan and Ness in the system (not to mention the wildcard de Haan), with Hamonic already entrenched, I think that poolies' hesitance with this guy is at least somewhat justified.
Just my take.