If it was a -DF engine he probably would have been able to hover on one engine without entering the water
Don't have any idea what the performance capability he might have had (altitude, gross weight, temp etc) but was obliged to do a single engine run on landing in a 412 at one time, sea level, 3-400 lbs fuel, plus a number of pax, after unloading pax hover taxied back to the apron. The very low RPM at the end suggests to me no drive at all.