I am curious to know the rest of the story as it could be quite reasonable. Absolutely if this was going at road speeds down a major thoroughfare, this is stupid and deserves a ticket.
On the other hand, this could have been a one-time move a 1/2 mile down a country road at 10mph. An overzealous cop would certainly see it as illegal, write a ticket, and make a Facebook post. A more reasonable cop might toss the flashers on and help a local guy out.
We don't know the rest of the story, so until then I will reserve judgement on the level of stupidity involved.
-Eric