I guess some of the headlights could be bad but what quite a few of us have found out is there was a film on the outside lense that was causing a problem, not a leak. This film can be easily removed with 3M Plastic cleaner which is available for about $8 a bottle from 3M's web site. I had that issue with my drivers side headlight, had made an appointment to have it replaced and then read about the cleaner. I would guess in your case a diligent service person knows about the problem and did the fix for you???

Pat