It really did a number on the filter, could not take it off.
The filters seem to shatter quite easily, especially a sideways impact to the filter ring itself (I have broken 3 this way). The glass shards can scratch the front element, which is less likely to be damaged by such an impact, being embedded further in the lens, and being made of thicker/tougher glass.
Filters give some protection from objects coming (not so hard that it breaks) at the front element, such as airborne abrasives. They also complete the weather sealing on some lenses. Don't however assume that the filter broke instead of damaging the front element.