Abiding by the rules and still injuring someone anyway is OK then?
people get injured by downwash - it happens, it's not great but it happens.
If the pilot had done something different, compromised his aircraft safety and spanked in after an engine failure you'd be calling him unprofessional.
In this case he put his ASS and that of his crew/pax first and made a safe (for the aircraft) departure - unfortunately the conditions of the day plopped his downwash onto someone (who he wouldn't have been able to see was there anyway).
It all sounds like a lot of fuss about very little and the low likelihood of the downwash from a helicopter at 200' affecting things in the garden would mean the majority of pilots wouldn't even have considered it a danger.
If people want air ambulances to get close to incidents then sometimes this sort of thing will happen.
I wonder if the injured party over-egged his assessment of the 'tornado' for compensation.