I'm 99.99% sure its a problem with the server not properly serving the collision meshes for the custom models, a lot of which were used as buildings to overcome source brush limits. The map is 6 years old and this ain't never happened before.
I just tested the map locally and was not able to reproduce the problem. This is an issue with the server. Case closed. Edit: Map is removed from Eurpoires. Looks like linux doesn't like my file naming.