If you are still under 30g for the day it will be fine.Liver is to good for you not to pass up having some now and again.
He does mention also avoiding 10 grams per meal though, which was my concern, as I'd definitely go over. I'm thinking it could go with a carb meal anyways, and I don't think you're supposed to have liver more than once a week - I've always cooked it in wine and served with onions, so I guess I could be a bit more liberal on that end as well. But agreed, it's too good for you not to find some way to incorporate it.