It probably could have been, but how likely is that compared to with the AI agent? I'd assume (and I'm ready to look like an idiot if I'm wrong) that the humans are trained to send the verification code to the email address on file, rather than any address the client asks them to. I'd certainly assume most of them are more afraid of the consequences than the AI is.
For sure. Social engineering attacks on human support staff are common and well known, but the skill floor is non-trivial; you need to actually be able to convince a human of your ruse.
Having a support agent likely made it easier to enumerate the vuln, and certainly made it easier to scale out exploitation once it was discovered.
