linuxmemes

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.