I'm assuming that the sleeve being flung up is the one not being printed...because if it is the sleeve being printed I have no idea how that works. Our CH3 is always set to max index speed and we've never encountered that problem.
Now, I have encountered that problem years ago on our G2s when printing sleeves on a very sheer fabric garment. So I got into the habit of after loading the sleeve I would flip the other sleeve over the arm, right in back of the sleeve pallet. It also prevents the sleeves from dragging on the ground.
Of course, if your press has ink there it's going to be a bad time...but it's far easier to deal with that than a spot gun on hundreds of sleeves.
Been doing it so long that I honestly had to scratch my head and say to myself "why don't we have that problem?" ...took a minute to remember that we did.