Been cursing the fella that does so many ties myself recently. Must tie that tube off at least 4 times. . Once is plenty if done well, particularly with it being hidden behind the outer bag tied up.Just heard of a guy near here with a broken ankle after a strap broke and knocked him off the side of the drill.
Bags are pretty well designed these days not to catch on something and open while moving, it just means the emptying spout is tucked up under the outer skin of the bag, also the emptying tube seems to be tied and tied again and again just incase, doesn't seem necessary to tie it that often makes them pretty much impossible to empty without reaching under or cutting.
Did i mention they tie the tube once more for luck.