The fun thing about action scenes. You can break the glass all you want and there are not repercussions; like glass shards being caught in your eyes or you breaking your hand or elbow.
This is why 2D will always be superior to 3D/CGI stuff. Is and always will be in a whole different league of its own. That's why the Academy awards should be separated in 2D and 3D/CGI animation categories. That's why Miyazaki never won the Oscar. Damn you, Frozen.
That is pretty much how all safety glass shatters. It stays together pretty well even when broken and the fragments are all blunt and farily consistent pebble sized. Really amazing bit of technology.