Since nobody responded yet, I will give my opinion on this based purely on conjecture. As indicated I do own a Hyperflow, and I have had the "Airlock" problem occur. Other than that I have enjoyed using the filter as it is light, small and has a decent output rate. From visual inspection of the filter after a trip where it airlocked several times during attempted back flushing, I don't see any physical damage to the filter element. So I would say that it is a myth. Unfortunately there is no way to prove it though. I could run the test given in the instructions to see if there is an issue, but even that does not appear to be definitive from accounts of others that have run the test on "good" filter elements with uncertain results. So that's my 2 cents for what it's worth.