Or perhaps this is a North American pilot used to a Transition Level of FL180. They fly across the pond where the number of Transition Levels between Ireland and Russia equal the number of aircraft in the sky and they made a simple, albeit serious, mistake.
Rather than specifying a "lowest available flight altitude," Europe seems to favour "lowest Transition Altitude." It's quite a different concept and a very easy mistake to make that has absolutely nothing to do with the professionalism of a crew flying a corporate or airline gig.