Yes it was incidental head contact but there are 2 factors working against him:
1. He chose to bump instead of tackle
2. He left the ground to perform the bump. This usually means high contact will be made.
Last season, Danger gets off no question even though those 2 factors mean he shouldn't.
But with all the renewed attention around concussions this season there's no way the AFL can let him off. He should get 3 weeks. Because it's Danger he'll most likely get 1.