Ark:
Helicopters are prone to "midairs with themselves" - rotating things at high speed close to a tailboom is an occupational hazard, if you will, and the teetering head doesn't help, for sure.
R22/R44s aren't the only ones who do this - a B206 lost its main rotor in flight about 8 years ago, and although the cause wasn't fully determined, mast bumping was the prime suspect see (
http://www.aaib.dft.gov.uk/cms_resou...pdf_500156.pdf for the report in full).
I think the issue here is not that the helicopter did something wrong, but that the pilot got into a position where he found it necessary to make inputs which lead to the final result. The precursor to that? Flying into cloud. Not much about the helicopter design implicated in that stage of the flight, I'm afraid.