I think it's a bit unfair to knock the bloke just for being trad. If he's happy cleaning windows that way, then that is his choice.
He obviously knows about wfp.
What I find questionable and as mentioned above is the idea that there is a safer way to get on to a sloping roof and go up the tiles. There isn't a safe way with unsecured ladders and without something to stop you if you slip, like a properly secured kick board to stop the fall from the roof, so the question of 'safer' is in reality a fallacy, It's more of a case of 'I havn't had an accident yet' so this is the safest way which is confusing acceptable risk and taking precautions with 'I've been ok so far so it's safe'.
It's like dangerous driving when the driver bases the risk on not having had a pile up in the past.
There again, if you're going to clean windows that way then maybe a bit of advice is good as to how to reduce the risk as far as possible.
Then that ignores the law that says you should always have at least two ways available to clean windows, one with ladders and at least one without using them, and always choose the safest option taking into account the job being done. In reality, the only real test of what the law dictates is when an accident happens and the person ends up in court.