I get the feeling that even if the technician called, and there was snow outside, this customer would have still instructed the technician to come out to attempt the installation since he had taken half a day off from work. Dish isn't going to cancel a potential upgrade due to a possibility of weather. They've never done that and never will. In a industry that is as competitive as satellite TV, one reschedule could easily equate into a new customer for your competitor.
As far as whether or not to risk his own personal safety for someone's viewing pleasure......heck no!!! I wouldn't do it. If he gets on his roof all the time in inches of snow, that's his business. Its his home and he takes the risk of leaving his family destitute as a result of his carelessness. As for the tech, he has to make the final call. I can't tell you how many customers rant and rave because you won't crawl all over their roof in an unsafe manner, or through puddles of sludge under their home so they won't miss Bonanza and One Life to Live reruns.
At the end of the day, if you fall and crack your back, or put in a pole and hit a gas line, or drill and pop a water line......the customer WILL wash their hands of any responsibility. And after saying things like, "I have no idea why they did that", they'll have some other schmuck out there to attempt something unsafe again.