I make it a habit (an unbreakable one) of looking at the electrical work in every place I go. Taco Bells are not "haywired" in this area, nor are any of the major fast food chain stores.
I'm sure that there must be a corporate policy in place with regards to employee safety, which this repairman has obviously broken. Is he a TB employee, or an outside contractor?
A letter sent to someone up the chain of command should at least get some attention. No large company like TB can afford to ignore safety complaints. I'd try that route, and if you don't get results, then OSHA would be a logical next step.
Yes, there are laws against retaliatory firing of an employee for "whistle blowing", but you might find yourself suddenly terminated for putting too much sour cream in a burrito or something stupid like that.
(BTW, the #10 connected to a #14 is not necessarily a violation, it would depend on the overcurrent protection and the load).
More power to you...S
