not taking up for the installer, but yes it is true that it is against osha regulation, and company policy. (example he has his shoes off drops receiver on his foot, breaks his foot, his company can refuse to pay him/dr ect and also fire him for not following safety regulation, being in proper uniform ect ect, you know how big companies can be) but he should have at the very very minimum had shoe covers to put over his shoes. Alot of installers have a extra pair to wear inside on muddy days. Myself i wear the shoes covers at every job i do, whether it is a multi-million dollar house or a house that already has more dirt on the floor inside than they do outside in the yard, and whether it is desert dry outside or snowing, raining.