He spoiled it specifically to ruin my enjoyment and investment in the characters. He is a spiteful douchebag at the best of times.
He spoiled the death of a major character...
Here's the deal: you'll be fine, I promise.
I've read the bulk of that series
5 times (long breaks between books cause me start from the beginning whenever a new one came out) - and I still get choked-up every time I get to the scene I think you're talking about. That's because the
personal impact to the reader is the
scene as a whole, not the event (though, how the event goes down is pretty intense in its own right).
I guarantee that if I sat down and read the series
yet again, that scene will still have the same effect on me. As a matter of fact, each of my subsequent read-throughs were even better knowing what was coming -- mainly because I was able to view that character's actions in a different light (though, with your late start, you'll probably not get around to that).
Point being, you'll be just fine.
Though, that dick who dropped the spoiler still needs to be brought to the Hague. Don't talk to that guy ... about anything ... ever.
And if he did indeed lie to you about who it was .... well, what I've said still stands.