as happened to me at an outstation a few weeks back. Arriving for an early morning flight to London I found the CE queue with about 25/30 people in it and no one in the ET lane. Thinking this odd given that CE is about 4 rows, I asked one passenger who didn't know the difference between classes - turned out they were a group traveling together and picked the first lane they came too and as there were no CE passengers at that time the outstation staff accepted it.

Thankfully, one agent recognised me as a regular and called me forward.