Definition of "Rotation Speed" vs "Lift Off Speed" vs "Fly Off Speed"
Your original understanding is correct.  Rotation speed and liftoff speed are two different things, the former being the speed you are to make an input, and the latter the speed at which you get a result (weight off wheels).  

That's almost certainly a typo and is supposed to say 75kts (my guess), which would be the demonstrated maximum distance to weight-off-wheels with rotation initiated late in the 70-75 kt range. Manuals published as integrated handbooks like that tend to never get revised unless a new edition is published, and the Cougar was only in production for a couple of years making a little over 100 aircraft, so I'd be surprised if there is a newer edition than the 1978 one, especially if it involved publishing a new handbook over a minor typo on an out of production airplane.

On a light aircraft the input and result are just about instantaneous and a rotation initiated at 75kt will result in a liftoff pretty much at 75kt or maybe a knot or two higher.  On high performance aircraft rotation speed and actual liftoff may be 1 or 2 seconds apart and it's more obvious that they are different things.