Single Send API sendResult seems incorrect

Hello,

I am experiencing a unexpected result when I query the status of a email send using Single-Send API
If I make a call to the Single-Send API to send a email (https://api.hubapi.com/marketing/v3/transactional/single-email/send) and in the "To" field I put a email address of a domain that does not exist (IE. abcd@dkjsdfdsjfk.com), I would expect to see a result of “INVALID_TO_ADDRESS”

However, when I query the result
https://api.hubapi.com/marketing/v3/email/send-statuses/{Id here}
I get the following

“sendResult”: “SENT”,

“status”: “COMPLETE”,

This was not what I was expecting, I could understand a result of “PENDING” if Hubspot would retry a few times. But it’s been almost 24 hours and the status is still “SENT”. When I open up the contact it does show me that there was a error sending the email

Please let me know why my status is not what I expect on the send-statuses call
Best regards,
Dominic Rooijackers