Cowling gasket

Has anyone have any experience in finding the cowling gasket installed backwards on a 4 stroke, 150 yamaha? I found this to be the source of a corrosion issue inside the cowling. I bought the boat new (Century 2400 Walkaround) and believe the gasket come installed backwards from the factory. The engine is still under warranty and Yamaha Customer Service would not honor the warranty to repair the oil vent hose nipple. The power head had to be removed to make this repair due to the corrosion on the hose nipple and my cost were around $1200.00. Any experiences out there like this?

Just guessing but your gasket probably got upside down during rigging or during some servicing or oil checking. Also, do you have any errant spray from a transducer or incorrect motor height? I actually wonder if it is possible to latch the cowl with the gasket out of position. just wondering.