That is true, same goes for the bunny hopping Gardner glitch and the "Pilot Light" achievement glitch.
With the bunny hopping one, you barely hit the ground at high speeds so for that moment the game doesn't have enough time to register that as "landing", hence you can keep the Gardner crits as long as you keep going fast enough.
And as for the acheivement, you just jump while charge shotting with the CM5K and it light you on fire, and the game just counts that as mid-air ignition, so it registers the acheivement, though I think they fixed that one a few updates ago, I've forgotten.