I posted the clip of the Wing Chun vs. Mantis friendly sparring clip from my personal video. I have met both instructors. Both are formidable fighters. You said "I hope neither of these is representative of their style" What criticism are you levelling, exactly? How would you advise them to spar in a safe manner that's different from what you saw? Would you offer a sparring clip to demonstrate what you mean?
I ask because the level of criticism I have heard regarding this clip is bullsh!t, so far it's been entirely from people who would get their asses whipped by either practicioner.
People think that fighting is all perfect like you see in the movies, or that you can spar all out no gear without getting hurt. Let me ask you, did you see Frank Shamrock fall over executing a kick and getting his ass whupped on SpikeTV? Would you then say FS is a laughable representation of the MMA style? The man has won the UFC title many times as you should know. When people are of similar skills the fighting is not pretty and anything can happen.