Yes it was, some people jump to conclusions way too early. It's just something DH wanted to do to cheer doing free throws while on the bench, it has nothing to do with mockery, just fun.
I believe the ref told him to stop just before he shot, because the ref gave him another shot. Not as funny that way though
I don't think it's just that Dwight feels bad about taking Omer's minutes. I think Dwight genuinely, desperately wants Omer to stay. He desperately wants to win a championship, and more than anyone Dwight knows the value of a good center, and of having 48 minutes of rim protection.
Dwight knows he Omer can really help in a championship run. Also probably feels bad too. DH seems like a pretty nice guy in general
the gif where Dwight is laughing is completely different from Omer's shot gif. the ball bounces high off the rim in one, and the other is where omer just airballs it