This is like the tech equivalent of consulting the village shaman or wisewoman for some serious disease.
Some decades ago when I was still an engineering student, my team had to present an electronic assignment. The damn circuit didn’t work, no matter what I did. So I decided to go ask the teacher for advice. I walked away a couple of meters, when my teammates told me that the circuit finally started working. As soon as I went back, it failed again. We soon determined that it failed only when I was near it. My teammates presented the assignment while I was at the other side of the lab. We passed the assignment, and sure enough, when I approached again to pick up my things, the damn circuit stopped working again.
It could be you wore the kind of clothes - certain shoes, wool pullovers, clothes made of certain plastic fibers - that makes one accumulate static electricity, so you literally had a charge different from the rest (did you have a tendency to get a shock when you touched large metalic objects or other people?)
Or maybe you were the biggest person on the team and hence caused the biggest electromagnetic shadow on the surrounding electromagnetic radiation (nowadays we live surrounded by radio sources). A similiar effect would happen if you had a less dry skin and hence more conductive than your colleagues (was this, for example, early morning after you took your daily shower).
Anyways, somewhere in that circuit was a wire which was unconnected and led to the gate side of a transitor, probably a Mostfet. If you were using a microcontroller in it, you might have left an I/O port enabled that was not physically connected to anything so its value could easilly flip merelly from electromagnetic interference and that day you just happened to have the biggest electromagnetic footprint (due to static charge, body size and/or body conductivity) around.
For fun it’s not hard to make a circuit that “detects people closeby” using a transistor or microcontroller I/O port connected to a wire that goes nowhere with the other side set up to light or not an LED depending on the input signal, which detects people because them being close or not alters the electromagnetic radiation that goes into that wire (an unconnected component pin also works, but it’s more sensitive with a bit or wire). The simple version is not exactly reliable, but it’s pretty spooky when it works.
Reminds me of the story of a company whose internet connection would cut out intermittently and they couldn’t figure out why. Details hazy but the gist is here.
One day they have a tech come in to investigate the problem. He goes downstairs to where the router is, and everything’s fine.
Seemingly the moment he goes to leave, the connection goes off. Panic stations! He goes back to the router and the connection is re-establishing. OK. All tests fine. He goes away again. It goes off again. What. Tech aura is real!
Nope. Turns out that when he went downstairs, he used the stairs. When he was coming back up he was lazy and used the lift.
The lift motor had been causing enough EM noise to knock out the connection whenever it was used.
