Webkit was likely "saved" by the original KHTML license being GPL. At the time, Apple were wise enough (or desperate enough) to figure that they could work with such a license, although they were eventually careful to chisel out anything they could into BSD-licensed modules. And still they had to be dragged into the light more or less kicking and screaming (e.g. they had no public VSC until KDE people kicked up a stink in the press, and were just throwing huge swaths of code "over the fence" like they still do with XNU).
If i remember correctly KDE used to be GPL when webkit started, and was later relicensed. The difference is relatively irrelevant anyway, the way they used KHTML they would have had to release sources even under LGPL. Had KDE used BSD, MIT, or Apache, back then, we likely wouldn't have had webkit.
