If someone falls down, you pick them up. If someone’s in trouble, you help them out. If someone shoves you, you shove them back. And, hell, if a bro wants to risk life and limb crowdsurfing towards an open mosh-pit, you better put your back into getting him up. The standards of throwdown etiquette at Slam Dunk were next level, though, with numerous punters visibly risking their own safety to help out fallen comrades and several getting down on hands and knees to provide less experienced moshers with human launch pads. Special shout-out to the lad who clocked our Cancer Bats shirt and tapped our shoulder between songs to politely ask if we knew what time they were on – then spin-kicked us in the chest the second that next China cymbal hit…