Actually I think it is possible.
I was out stargazing/meteor watching with friends last year near a local observatory, and there was a really bright light to the southwest that we couldn't think of what it was, some were thinking had to be (as it was bright, moving a *very* small amount, and looked almost exactly like Venus does), but some didn't think could be Venus (as it should have set). Going on however long, probably close to 20 minutes, it starts moving more, and eventually we are able to see what it is: an aircraft with it's landing lights on, eventually passing nearly overhead. For about 10 minutes, we didn't know what it was. (And then we started suspecting an aircraft as the apparent brightness and movements were greater.) Oh, and If I recall correctly, we had 2 people with AE degrees with us, and several people who work with aircraft for their jobs (actually probably half the group). If we didn't figure it out that quickly, I highly doubt anyone with less experience of aircraft would have, before they pointed it out.
If any of us had been using green pointers, I highly suspect someone would have pointed it out that way, as opposed to pointing it out verbally and with fingers. The only remaining questions were how far away it was, if we'd have had the power to be visible at the distance (at 5mW, unless the beam was really good, I kind of doubt it), and if we'd hit the cabin. Granted, they were not on final or anything (they did seem to be a little lower than expected). That experience has suggested to me that it is fairly likely that at least some of them are likely to be accidents.
I can't find the lower limit of human vision, so I can't tell, but if we assume say 400mph, It would have been about 40 miles away before we decided it was an airplane. Which would put even the blue spyder lasers in the harmless (it gets there before 2 miles (with blink reflex)), but visible category. A 5mW laser might not even be visible depending on divergence. (5mW is the limit of what get called laser _pointers_ are supposed to be restricted to. Finished products of more than 5mW aren't supposed to be called laser pointers, but everyone seems to ignore that.)