I've seen a lot of dogs get confused switching back and forth between EV, SR, and BA all in the same day the first couple of times, so I wouldn't sweat it, especially with the changing light conditions. I make the picture for each event really different for the dogs and that seems to help. For BA, the dogs may wear their suits (they dont for SR or EV), and I do the typical sit stay at the end of the dock, me at the edge on the other end, toy in hand. For SR, I show them the bumper, drag them back, hold the dog back on the line, lean over them, cuing "reeeeaaaaddddy, seeeeet, GO!!" in their ear along with the cadence. For EV, we do a stand stay (or try to) on their mark while the bumper is placed, I'm standing at their side, and then I release with "Get IT!" For both SR and EV I have my double string bumper in hand in line to keep them targeting the right item and I drop it before going on the dock so they can get it on the way off the dock on the other side. Dunno if any of that helps or not, but figured I'd throw it out there.