I think Michael made it all clear in his article, he also writes that he has been wrong (and should have known). The article is about warning people for making the same mistake as he did. And trust me, LOTS of people bring their personal watches to Basel to wear during their different appointments, diners, events etc. So this article is warning them.
Whether it was clear to him that personal items are different from the requested ‘commercial goods’ is doubtful. In the end you should declare everything, including the laptop or camera that you will use during your work in Basel. Better is to get a Carnet form.
So, Mike made a mistake, wrote about it, including his experience during the whole event, blames only himself and warns others to take care of this. People who call him a bad journalist should take a brief moment to reflect if they never made a mistake in their professional life. Such a comment makes little sense.
If people (collectors, journalists) will think of his article next time they go outside EU (or vice versa) for a watch event, they know they should either just bring one or arrange a carnet form. If his article prevents someone from making the same mistake, it already did its job.
That’s all I have to say about it basically, it is not my article so I can’t really speak for Mike.