Sunfish beat me to pointing it out, but we weren't there, perhaps this particular person was not up to standard on some sequences, may be 4 of his 6 stalls demonstrated poor recovery techniques and it took a total of 6 before the instructor in question was satisfied. On the other hand the instructor may of been over zealous, without being there we will never know. There tends to be two sides to a story.
I do recall from my instructing days that you would get the occasional PPL holder that would feel that doing a BFR was a waste of their time and money because they were of the opinion they were good enough already and did not need to prove it, and they typically (not always) were the ones that needed a BFR the most (most likely due to attitude than ability). It is that type of person that I would envision writing the above mentioned letter.
A quick scan through my logbook shows that when I conducted BFRs they ranged from about 1.3 to 1.8 hours duration, though this to me does not mean that a 2.2 hour BFR would necessarily be excessive, it does depend a lot on the candidate.