The marks were kinda to the side, so...good? I'm not sure how far from the "center" of the throat it has to be to be safe ("safe"), just that the middle is bad.
But still, that play without a safe word is a BIG no-no. With how wholesome this is, the author sometimes toes a very dangerous line. 50-shades-of-shit dangerous.
He actually pressed until her nose bled. Not sure how I feel about that.