RFI better know as Radio Frequency Interference can do weird and funny things to near by equipment. It overloads the equipment's frontend and electronics and causes all kinds of fun things.. Just like you experienced with the alarms that was on the tractor around the construction site. I bet if you move further away than 20 feet from it it might not have happened. I have been behind many of my buddies knowing they are speeding and have set off there radar detectors with my gmrs radio and other radios because i was close to them and overloaded the frontend of the radar detector. Funny as crap to watch them hit the brakes cause they thought a cop was around radaring.. RF can and will do very weird things.. That's why the FCC has RF Exposure limits on certain frequencies.
https://www.fcc.gov/general/radio-frequency-safety-0#:~:text=The SAR is a value,(1.6 W%2Fkg).