You can self-connect without going back through security if you happen to arrive and depart on services using the domestic pier, and it is used for some international departures. The fact you can do this makes the presence of the guy to turn you back a farce.
No one is going to risk that though are they? The overwhelming majority of international EZY flights go from Sat 1 so you'd be screwed if your connection is even moderately tight. If I have a valid boarding pass on the EZY app, could I turn left? In fairness, is there anything to stop a departing passenger returning to the lounge once on the 80 gates on Sat 2? It doesn't say no return....given that, what IS that security guy even doing there?
There used to be a similar thing at Glasgow where they had a security check preventing any arriving domestic passengers accessing the then new common departure lounge, no idea why and long since removed (!)