There definitely was miscommunication between the different parties involved and it could of been handled a lot better.
First of all, the riders involved should have followed park rules, either take off the head wear or get off the ride. If they wanted a refund, they should have politely stated their case and asked for one. It looks like the park ended up giving some refunds after the incident occurred.
Second of all, the Muslim American Society of New York were warned that headscarves were not allowed on the rides there and should have warned their members as it would most likely be an issue for some of them. They should have looked into other parks in the area without head wear/gear restrictions (maybe Coney Island?) and possibly have their event there instead.
Third of all, the park should have better prepared itself for a group of over 3000 Muslim American Society of New York members and had their staff warn members of MASNY (or those dressed in headscarfs) at the ticket booth or front gate that "head gear of any kind including what your wearing will not be permitted on the rides". At least then, those opposed to this rules could have the option of not buying a ticket and turning away. Its not like there were a few Muslims attending, there were over 3000 attending, so there was bound to be an issue with the headscarf.
Finally, it seems like the police were very vigilant. Was 100 police officers necessary for a few park guests arguing? Or closing the park for two hours? If the police officers were less vigilant this probably would have been a lot less of a scene, but sometimes they are "shoot first, ask questions later", not just in this country but many countries (especially the Middle East). I wonder if so many police officers would have been sent out if there wasn't a group of 3000 Muslims there (even though only a few were involved). To be fair, the park guests shouldn't have raised their voices at the police officers or seemed aggressive/threatening - I mean come on, don't mess with the police!
I'm just trying to see this from all points of view. It was sad for the park guests not involved just trying to have a good time to see this incident occur.