IO540,
In an R22, if you do nothing else, you have about 2 seconds to lower the collective. But if you flare as well, which also raises the RRPM, you have about 7 seconds - I know someone who's tested this. That's not a lot of time, but it should be enough...most people's reaction time is far quicker than this. So this is what we teach students - lower the lever and back on the cyclic. And we practise it lots!