This makes no sense. Why would there be any less liability for an employee killed or injured by a criminal, than for an employee killed or injured by an accident? Especially when the first case could be directly affected by the policy that denies them the tool to defend themselves?
Some of our legal experts have opined that there IS liability on the part of companies who deny self-protection tools. Perhaps we just need a very high-dollar, high-visibility civil liability case to wake up the corporate attorneys.
ETA: If the mentality you describe is true, what this tells me is that the corporate bean counters have been suckered into believing the anti-gun propaganda about things such as no real defensive use of guns, and gun owners more likely to hurt themselves than to defend against an attack, etc, etc.
TFred