Cold emailing in the B2B space is totally normal. He just wasn't cold emailing. The sheer numbers alone, combined with the fact that he used some scumbag data broker to get contact info, means to me that he was actually just spamming people.
If he had individually researched each company, then after deciding he could likely help them, looked for the right contact in their org and personally contacted them, he would have ended up doing the right thing right.
He would have ended up sending more like 80 emails, not 800.