Thanks bandit.

I went to the dealer today and explained what had happened. The mechanic, who's still learning English, thought he'd been instructed to take the mod out. They profusely apologised and reinstalled it. After asking if any damage had been done to the engine, their chief mechanic explained that the bike would have been running the factory mixture because the ECU would have compensated for the increased airflow. No idea if that is true or not. I remember reading something about the ECU only compensating for temperature change but I doubt there was serious damage done to the engine.
I guess these things can just happen.

Peace