I've worked as a GHA for four years now and going from BA when were "not so fussed" at your hand luggage to BMI Baby were they are very strict, and i truely agree with Ckin Gal saying that:
at my desk it is quite often difficult to see all the bags and pax do tend to put it infront of my desk so that i have to ask to see their hand luggage.
Don't worry though love, it happens to the best of us!!
Pax nower days are sooooo devious!