It does check the conflict as you mentioned that one event is allowed at a time.  More specifically, one event is allowed at a time regardless of locations.
Since a LOCATION can be created, the location should be a conflict checking location as well, because an event can be occurred at the same time but in different locations.
Another suggestion:  When a conflict(s) occur, it is better to display where the detailed conflict is. This is especially useful for recursive bookings.
Thanks for your wonderful work.

Thanks very much Roger. I would like reword what I've said in my previous thread:

"Since a LOCATION can be created, the location should be taken into account as a conflict checking variable as well, because many meetings can be held at the same time as long as they are in different locations."