Ned was long dead when he said that
Jaime showed Ned a tremendous amount of respect...and relished the opportunity to knock down the great Ned Stark.
The show is based on the book, but they've made changes in certain areas. If they up and turn Robb into a closet homo (you know that whole gay agenda this country can be on sometimes ) you can't argue that Robb ain't homo. The book can only be used to make an arguments regarding the TV show story if it doesn't directly contradict the what the TV show says happens.
And you ask who have I seen OPENLY challenge Jaime....just one person....old ass Ned Stark, and they fought to a draw.
Ned was fighting for his life, Jaime was fukking around for the lulz.
Why would the TV producers change the lore to make Ned a beastly swordsman? What purpose would that serve?
Either the writer for that episode thought "Okay this George R. R. Martin source material okay, but I think I can make it better by writing this episode as if Ned is an elite swordsman and > the Kingslayer"
or you're extrapolating too much from that aborted duel. I think B is more likely than A.