Honestly, it doesn't shock me in the slightest that someone who markets themselves as an SEO expert would not only do something as unethical as this, but also brag about it, as though they think they've done something they should be proud of.
Is this that different than publicizing bugs? He tested it for a small amount of time, noticed a real security vulnerability (he could collect leads), and publicized his findings knowing Google would likely punish him for it. It's mildly unethical at worse, considering he could have happily done profitable leadgen at scale and it would have likely never been caught if he kept quiet.
"Small amount of time"
?!?