Having worked for comcast through a contractor for a bit over 3 years. I am also not surprised. Training is non-existant for their contractors. The comcast first party people I spoke to in the process of doing my job were actively hostile and did everything they could to avoid doing any more than the absolute minimum needed to keep their jobs, as often as not hanging up their phones on me as well. And no the comcast first party I spoke to were not aware we were contractors, so they are hanging up on eachother just as much as customers.
There was no way to communicate special circumstances to the in home techs outside of a series of about 12 'special instructions' checkboxes. Which were using so much shorthand as to be completely indecipherable even by my managers. And while there was a place to write in additional details, when I ended up just at random getting a work related call from a family member, I put in special instructions. They later informed me that the tech never saw anything I wrote.
Comcast sucks. Working for comcast sucks. And while I agree that that dude should have put more cones at the top of the hill regardless, if he did that, and one of his overseers drove by the site to check to make sure he's working (which they do) he would have gotten a write up for wasting his time by putting cones up so far back.
SRO techs causing an accident with injury? No big woop. Probably happens all the time just nobody gets it on film. Comcast is just going to wait til people forget it happened, maybe settle out of court any civil cases that causes, and continue swimming around in their scrooge McDuckian vault. At least the SRO techs showed up, they usually don't.