Hmm! Well, I’ve gone through a few different opinions on that, over time.
But I have to say, right now, I have a certain fondness for author Brian Daley’s interpretation in the official Novelization:
which I discussed some more, in the wider context of the story arc and its themes about presumed death and misunderstandings
Basically, I kind of love the idea that Flynn was such a random loose cannon that he helped take down the villains without them ever totally even knowing what was going on.
Sark never even found out that the guy he met in that scene was the User that the MCP brought in (a User that Sark never saw up close, and may have never even known anything about, not even his name!) He just thought he was Clu, the program that had died at the beginning.
And Sark and the MCP both died without ever knowing how much Flynn was involved in taking them both down.
I like how it makes Flynn, from their perspective, just a sort of… forgotten nobody.
And a forgotten nobody can make a difference.
And… well, I like that.