I have not ever participated in a PCA event, but they do have their own rule book and safety regulations that differ from SCCA. I don't know obviously if the finish runoff area was/would have been sufficient in size.
My immediate feeling is this was a direct result of driver error and indirectly a result of the proximity of physical obstacle to the course.
Trying to "save" a spin is ALWAYS a driver error PERIOD!!! Trying to save one AFTER the finish by application of throttle (in a 427 Cobra replica

) was DEFINITELY a MAJOR (unfortunately fatal in this case) error!
A similar driver error at an SCCA national event in Ft Meyers resulted in a nearly totalled Subaru.
My sympathies go out to the family and friends of the unfortunate driver, but this accident could/would have been avoidied had the driver followed the # 1 AX safety mantra: IN A SPIN, BOTH FEET IN!!! Let this be a tragic lesson for all.