With what you are saying about engine oil in air filter /airbox it’s an overfill .Its impossible to say on a hot bike how low is the oil level .Im telling this based on SFV4S experience.Maybe you should take it to a different dealer and take a second opinion.
It was blown piston rings mate, not overfill. Even by lowering the oil to min, there was blowby. But now its been fixed with the new engine.