hey simon,
i somehow can relate to your point here and somehow not.
for me it was last year, that i really got pissed off by the crowd. it was not one incident but several, where i thought: "what the hell are you doing here"?
there is always this dynamic when the band starts and mostly some people who are not used to it get blown away.
i wanted to go a bit further in the direction of the pit and because its crowded i had to use a little, but pleasant pushing, to achieve this. i was excusing myself and mentioned, that in several seconds, all people standing here, will anyway be "pogoed" in another direction.
i did this so many times at concerts, the first gig being in 1989, and never had problems. but last year (2016), me and my friend were shouted at aggressivly and there was a tention in the air, so that we stopped and just waited for the mass energy do do the job.
i witnessed several other almost fights in the crowd, because of that and all of that affected my mood and remenbering of the concert in whole. there was also this stupid pushing from behind of the people who stand there and just push you with full force, better said hit you in the back again in the moshpit...
but this year i found it better, i snaked my way to the middle, danced furiously and witnessed nothing of that you wrote about. there was this guy though who suddenly grabbed me by my throat and pushed me, i grabbed his hand and for a second there was a fight about to start(i never was in a fight my whole life though. just got beaten up;-), but i gestured that his move was totally inappropriate, i don't know why he did it maybe i bounced into him, and then we embraced each other...
that what you wrote about is really annoying but maybe just an impression of some actions occuring and hopefully just a misunderstanding...