It is all about the size of the bubble. Large bubbles that enter the fuel pump compress halting the fuel flow to the engine. Large bubbles entering the engine can knock out the flame front. The demonstration clearly shows that if the air is broken up into smaller packets then the interuption is minor. We are by no means suggesting that you should fly with a low level in your air trap on the contrary any air in your trap could mean that you have a fuel pickup issue. However if you practice extreme aerobatics or you do suffer an inflight air leak into your fuel system then a well engineered design will help to keep the engine running and give you a better chance of a safe landing.