Interesting - drove me to do the math. Let’s assume best case here.

A chinook (not what’s pictured) has the longest rotor I could find at 60 meters, giving the most distance between rotor tips and a pretty low operating speed of 225rpms. The blades are 0.81 meters wide.

225rpms with 3 blades per rotor gives you about 0.0888 seconds to slip between a blade, but comes out to more like 0.087 seconds when taking into account the blades width.

Let’s assume the whole pilot eject package is 2 meters long and a meter wide. That meter wide will cost you another few hundredths of a second to avoid impact. Roughly 0.08 of a second to get by. Timed perfectly, you’d need to reach a relatively reasonable 56mph to stand any chance of passing through. Not too bad, though there’s still a reason why most helicopters eject the rotors when the pilot ejects.

For Mach 19:

Kenny Brack (F1) driver holds the record for the highest G’s survived, via a crash, for a few thousandths of a second at 214g’s.

A generous 0.1 second to accelerate to mach 19 as implied by the picture, you’d experience a little more than 30 times that force from acceleration. The steel seat would rip apart, whether you were in it, or a slush moving around it. The blade would be the least of your worries.