"The driving standard is poor in that he had to cut in front of you to avoid a collision". I think that misses the point. He only had to cut in front of me because he attempted an overtake which any reasonable driver could see was going to be very risky.
"...the fact that there was no collision... provides an element of mitigation" What!!! So, if there's no actual collsion, that's OK, then?
I think this is a good outcome.
A prosecution may just make the driver cross and make him a little 'anti-bike'. It may (or may not) alter his employment position. Any of the above might be argued to be undesirable outcomes.
This way he has to sit and watch what he did wrong and listen to someone telling him how he might modify his behaviour in future. That is straight out of several texts on addressing poor behaviour and ticks every box apart from the rather questionable one of making the malefactor stand before the bench.
As to the 'standard is poor' quote, I see as implicit the suggestion that the standard was poor prior to cutting in front of you. The author does not limit his comment to a single action in the footage.
On the 'element of mitigation' matter, the author does not say it's 'OK'. He says that there is an element of mitigation and in that he has a point.
He clearly doesn't think it's 'OK'. Nothing in the email you quote suggests he thinks 'that's OK then'... Quite the reverse.
All in all, I think that's a very good outcome. In fact, I cannot think of a better one.
Top marks to the officer who made that call.