It appears the company has been in good standing wherever it does business. KUSA-TV hires the company, and I assume it's not the first time, on good faith that the company is following the law. I suppose the reporter could have asked why the security guard wasn't wearing a uniform or any other clothing identifying him readily as security. This strikes me as a Pinkerton problem first and last.
Total sidebar, Pinkerton's corporate offices show up as being in the same general area as Sinclair Broadcast Group in Hunt Valley, Md.