True, I got a little off topic regarding the NEC.
But in reply to the Tom's (OP) comment about 70E's legal requirement this should be answered here at this website
OSHA Enforcement of NFPA 70E
?Though OSHA does not, per se, enforce the NFPA standard, 2000 Edition OSHA considers NFPA standard a recognized industry practice. The employer is required to conduct an assessment in accordance with CFR 1910.132(d)(1). If an arc-flash is present, or likely to be present, then the employer must select and require employees to use the protective apparel. Employers who conduct the hazard/risk assessment, and select and require their employees to use protective clothing and other PPE appropriate for the task, as stated in the NFPA 70E? standard 2000 Edition, are deemed in compliance with the Hazard Assessment and Equipment Selection OSHA standard.?
The empolyer can I be cited for not complying with NFPA 70E so however this fits into your definition of legally required the truth be known citations can ensue through a randum OSHA inspection.