Yea that's very possible. Either the internals in the transmitter could be off or it was what is called Imaging by the aircraft receiver. I used to have about four police scanner going about any time. I had them hooked up to two outdoor antennas and on a signal booster. I could hit a good ways out as far as reception went.
On my older scanners without triple conversion I would pick up frequencies about 21. something MHZ above their actual broadcast frequency. A Pirate operating on the upper end of the FM Commercial radio band 106-108 MHZ could in theory IIRC image into the aviation frequencies especially on older radios.
That's also how Newts cell call was likely intercepted. Many years ago right as cell phones started to get popular some older scanners could pick up the cell phone frequencies and because calls were analog everyone could hear them. To try and stop it the FCC forced the companies making the scanners to drop the cell spectrum. Only Licensed Techs could purchase one with those capacities. But triple imaging scanners had not came out yet so analog cell calls were still being intercepted through Imaging up in the 800MHZ. Finally the scanners went to triple conversion and the cell phones went digital. Newt was likely heard on a scanner using imaging.
I remember a couple of comical things that happened in a nearby town. The PD a cop and a desk cop were on radios in the 45 MHZ band thereabout. One nice hat late afternoon I heard "This is a national alert. Be on the look out for a white female long black hair 5'2" weighing" then it went dead. The voice was way too loud and way too clear. The accent wasn't local. The patrol cop and the desk cop started fussing with each other about one of them screwing around on the radio. I called their station and said I heard the alert on a police scanner. You were hearing Skip. The desk cop asked me who is Skip? LOL.
Second one was where a guy stole a handheld county SD radio from a local high school office. He waited a couple days then turned the radio on and proceeded to call officers he knew and the sheriff all the things that came to mind. The dispatcher kept saying this is not an authorized broadcast and baiting him to say more. In about an hour the radio went silent and a deputy said the radio has been recovered subject in custody. They triangulated on the radio. The dummy was in his living room. LOL.
An aircraft receiver picking up images from the FM broadcast band would experience far greater interference from the 50kw licensed stations on the band than from 100w pirate peanut whistles.
On the other hand, a sloppily constructed pirate transmitter could easily be radiating garbage on other than the intended frequency, and that could potentially bother pilots.
I remember being out near Worcester, maybe near the airport, and some kind of spur of an aircraft signal could be briefly heard around 98MHz. And near Boston I was listening to 96.9 when they were talk (WTKK) and heard a brief snippet of aircraft radio chatter suddenly come over it (plane flying over...?)
>>Many years ago right as cell phones started to get popular some older scanners could pick up the cell phone frequencies and because calls were analog everyone could hear them.
The film Sonic Outlaws showed a media satirist group from the Bay Area, Negativland. One member (now “retired”), David “The Weatherman” Wills, was shown using some kind of scanner and he was listening in on a phone conversation. It was a bit of an argument between two men (who, uh, were a bit of a “couple”...again, Bay Area!). Wills looks up at the camera and says “There we go. I think we broke the law, just then...”