OSHA violation?

Since people have been scratching their heads over the OK "guns allowed in employee cars" law was struck down by a federal judge, citing a conflict with OSHA, I wonder what to make of this story:

http://www.philly.com/philly/news/local/10664667.html

Robber killed in gunfight with recycling employees
After many holdups, the Germantown site's owner said, he allowed workers to carry guns.

I guess Cooper and Geppert can expect a fine from OSHA since they are "not abating the hazard of workplace violence."