Hell nah, that's equipment is just in the ball park of around ten grands max. A spilled drink might ruin one or two pieces of equippment, definetly not everything. Twisting on knobs does nothing expect shift a setting.
In a case in which he spills a drink or breaks anything, DJ can take him to civil court and make him responsible for the damages including missed livelihood. Court would possibly keep in mind this setting is in a place where people will be toxicated. So it's a part of the DJ's responsibility when choosing to pick his gigs. Regardless if the kid caused damages he would have been on the hook.
Medical care needed for that shove can rack up hunderds of thousands. So it's a possibility that the DJ now has to sell his gear for assulting a drunk party goer.