Luckily I'm not an SOB. I would tell customers not only if the filter should/needed to be cleaned, I'd also remind them not to saturate the filter when oiling it. I even had one guy whose MAF sensor problem was caused by oil saturation and to take it easy with the oil.
I'm betting this husband had to re-purchase a K&N filter at some point because an oil change tech didn't know what it was... Actually pretty humorous.
My Focus wagon had a 'life time' air filter...apparently because that's one of the things that get it to be classified as a 'P-ZEV' (Partial Zero Emmisions Vehicle). I still don't know how the two things are connected. The filter box, which was basically impossible to remove by a backyard mechanic such as me (I tried), had a little viewing window on it, which registered good (green), marginal (yellow) or red (needs replacement). Mien was always green, but I still wondered what kind of junk my engine was injesting with the air, after 65k+ miles....... A NEW filter, by the way, was something like $230.......
