The impact absorption of a modern helicopter is several times that of the McClaren that you highlight. Any helo designed to the latest standard (B429, AW139 and S92 come immediately to mind) can withstand about 18 g's, and must have seats that are twice as strong. I think these civil machines could rival the military machines that the US builds (most non-US military helos are no stronger than older civil machines).
Most of the civil helos we fly are designed and built to old standards and only about 1/4 the crash safety standard of the newest designs, however.