When to frog and when to accept the defect?

We all know the pain, you're so far in to the pattern and something happens.

This weekend I have restarted a Firebolt using Malabrigo sock 4 times and I've also had to frog my Trillian as I dropped a stitch in the lace section and to me it threw the who pattern out.

Normally I'm not such a perfectionist, there are at least 3 yarn overs in my Hitchhiker and I know I made some mistakes in my Shade Loving Shawl. I think I'd just like a pattern to go right for once.

When do you restart versus accepting its not quite perfect?

I've popped a picture in of the yarn I'm using for my Firebolt. It's gorgeous yarn and even better my LYS stocks it.