Hmm, interesting theory. One thing wasn't clear to me--has the bottle been on your desk in the print shop? Then that would seem a plausible theory. But if you mean your desk at home...I'd be more skeptical about there being enough solvents wafting around in the air at home to do this.

Are the graduated markings printed on the same way as the logo, with similar "ink"? If so, then that would probably be an argument against airborne solvents since they should attack all the printing on the bottle pretty evenly, I would think.