In my defence, there have been other tanks where people have said you have to close the airflow when you fill, or tip it before tightening up, where I've not found that to be the case. The Beserker Mini has never leaked on me, no matter what I've done - I just open the top, dump the juice in and close it up again .... no bother (well ..... so far anyway ........ sods law ....... I'll get teh wipes out ...... ).
I think we all do things different ways, and what works for some doesn't always work for others?