I find it hard to believe a mixed rooster would throw a good laced pattern like that, even if the mother was pure. that's like a 0.1% chance... I would say isolate her to be sure before judging... she could have just been checking out the nest but not laid yet, or had already laid elsewhere.
She laid the egg right in from of me. I know for sure it was her!
Oh yeah, and I called the breeder and he admitted he had another blue laced red wyandotte that was throwing olive eggs, he thought it was so cool. I won't be using him as a source any more, there is no way he should be calling them wyandottes if it is producing olive eggs. I'm really happy I have a olive egg, but I certainly shouldn't be getting it from my wyandotte.