What part of "Scot" didn't she get?

Okay. I didn't know McIntosh's first name was Charles, and I only guessed him because "macintosh" is a name for "raincoat" (as in "plastic mac"). But there was certainly enough in the clue to point me at him:

In 1823 this Scot obtained a patent for a process that made silk, paper and "other substances impervious to water and air"

Still, only one of them got it. One said "Carnegie" which is sort of reasonable, though Andrew of that name was actually born in 1835 and lived well into the 20th century and wasn't an inventor...

But ... the champion (though she wagered such a small amount she still won) said ...

Tesla? Tesla?

.