This person purchased a gift card code which is supposed to be give digitally.
Seller asked for email verification and he did not pass, because he checked another different email address ( he did not aware which email he used on PayPal at first, he has multiple email addresses )

Seller waited and waited patiently for the email confirmation by sending a verification code to him, but never heard back. Instead, another email ( from a unknown email address ) came to ask for the product.

Seller is not allowed to send a product to someone with a different email address, should he?
What if the original email account holder ask for it again if seller did sent it ? Sending numerous times?

Seller refused and insisted to have item given digitally towards the original email account holder, buyer got pissed off and started shouting.

Soon after he found its his fault not to check his original email inbox/junk mailbox, he complained to seller " I will publish your site/name worldwide ...... etc "

This is a poor experience seller had and should be avoided in the future.
Buyer did not think he is wrong but just pulled everything bad to seller's side.

Lastly, it could be a Nigerian scam that ask for digital item like those did in the past.