I kind of agree, but I think it would need to be more than just burning a Qu'ran, you'd also need some inflammatory speech, like "death to Muslims" or something that would be intended to move them to violence.

Regardless, I do think there are circumstances where burning a holy book could be included as evidence in a hate crime case.

Thats a realistic interpretation of what those bbqers intent would be, but I dont think you can realistically make that illegal as the sidewalk is a public area. (I am assuming these bbqers are not breaking any other laws at all.)