British Swimming have now received official notification of the statement of the FINA TSC:
Related to the new FINA Rules about separated hands as mentioned in SW 7.6 (Breaststroke) and SW 8.4 (Butterfly) please note the statement of the FINA TSC as agreed at the FINA TSC at the Meeting in Bangkok (THA) on 6 & 7 December 2013:
”Separated” means that the hands cannot be stacked one on top of the other. It is not necessary to see space between the hands. Incidental contact at the fingers is not a concern.
Pictorial examples of the interpretation can be found here.