Hindsight is exactly the problem here.
I'm sorry but that's just not true.
You can't get me to spend $10,000 simply by getting me on a video call and telling me it's super secret, even if it's the CEO and I have absolute proof that it's him. He'll have to sign me a paper, and he'll have to give me an account number that's either in our list of approved accounts.
It's not cultural differences, it's plain common sense: if I'm fired for refusing to pay something someone legit requested me to pay, I can drag my former employer to court for unfair dismissal - whereas if I'm social-engineered into paying crooks, I'm responsible and I can be dragged to court.
Besides, even if 15 totally legit officers ask me to do dodgy payments, it may very well be that all 15 officers are up to no good. It's my duty to refuse what they ask if it doesn't pass the sniff test.
I might have a hard time saying no to higher-ranking employees socially, but I won't say yes. As I said, ultimately, I believe the company wants me to be a barrier against fraud, and my work duty is to the company, not its officers. And a judge will side with me on that one if it comes to that.