There was a second NOTAM issued (07/043 I think), that listed a requirement for a PPR too with a phone number attached. It is unclear which was actually in affect at the time of the incident. I agree with knobcrk in this instance. There woudl either be landing slots or blocks of time between the practices that would allow for landing, but just showing up at ANY time and being cleared to land isn't going to work 100% of the time.