I just had a Modelo Negro and I am absolutely certain that this is a totally different beer (as in a recipe change). I haven't heard anything about this.
Is there a best buy or brewed on date on there? Possibly a 6 pack that had been exposed to lighting, sunlight or stored too warm. Is the change for the better?
This was my thought as well. Especially if he had it at a restaurant. It could have been old or stored improperly.