What can go wrong with not doing a water cannon salute? Nothing

What can go wrong doing a water cannon salute? Lots, as detailed above. In DXB the force of the water cannon blew an over wing exit door in an SV A320 soaking the passengers and blowing the slide. And the (inaugural MAN-ATL?) Virgin flight was cancelled a few years ago after it was accidentally sprayed with foam.

Of course, it's a nice gesture when it goes right! I was stood on the LGW N terminal bridge when the inaugural Rwandair A330 taxiied underneath and got a spray.