Little birdy in Seattle says that they were off on a jolly of their own, and since they had to pay for their own gas, they only put in 300 gallons. They flew from Boeing field to Paine field to do circuits and were probably having too much fun to notice the low fuel state. The hand-cranking of the gear is not related. They had to do that cos the hydraulics for that gear were powered by the engine that failed. Although they feathered that prop, they somehow omitted to feather the others when they failed.
So, big question. Why, after No 3 spluttered, did they make for Boeing field, instead of Paine field right underneath them?
Cos that's where their cars were parked.
Could only happen to top test pilots.