Yes, you're talking about the Formula BMW. And that's no glitch at all, go ahead and try shifting with no clutch and throttle wide open, good luck with that.
What you have to do to shift: Hold the paddle/shifter down, lift the throttle, let the gear engage, let the paddle/shifter go and push the throttle again.
He couldn't possibly mean the BF1, since that one has a completely automated clutch and therefore always shifts into the gear you select.