This is nothing more than instant jury nullification. ........................... Someone forgot to bring a rope?
The result of those actions was the arrest of the criminals and the recovery of stolen property, which is CERTAINLY lawful.
I haven't drilled down and doubt if I will, but I'll bet none of these armed citizens will be charged with a crime.
And if so .... then the law recognized an unlawful act as lawful.
NULLIFICATION !
No rope needed because the criminals will now be adjudicated by a lawful judge