They were on the homeward journey of an impressive trip from the Continent almost to the tip of the UK and back again, one in an open cockpit.
In that case I think I can work out who one of them must have been so I'll be keeping an eye on his YouTube page to see if anything turns up.
Like Maoraigh1, while I really don't think this was in any way hazardous it'd be better if it didn't happen. We're presently fighting off an airspace grab by Inverness and although this exploit occurred below their ambitions it is another small incident with the potential to be used for chipping away at our freedoms.
I know of several losses of facilities that were triggered by the exuberant actions of one pilot. So while I don't want to be a killjoy, we really don't need more.