I think that you're missing the point.It's not the bottle top that is the problem, It is a bottle with a top on that is the problem.
A full bottle with a top on will travel like a brick when thrown. A bottle with no top on it and with the liquid falling out won't travel as far or as accurately...
We're only a single incident away from introducing NFL style rules on clear bags of a certain size only.
Unfortunately it's the way of the world.
Within a few years I think it will be introduced as mandatory at all Premier League grounds.
Things are ever going to become more relaxed, they will...