Yes, it could be something like that.
Due to how the lavender gene works, both parents (not just one) would have to be half lavender or half Isabella or something like that. But if one rooster and one hen had those genes, and the other hens did not, then the whole flock would only produce a few...
That doesn't sound like recessive white.
The lavender gene can cause those colors, but would probably not cause large amounts of actual white.
I'm puzzled, and don't know what to say.
Maybe @nicalandia or @Amer would know something useful?
My first thought was that he might be recessive white, which is one of the more common reasons for a white chick to appear from colored parents. But I think I see some brown-ish color in his feathers, which should not happen with a recessive white chicken. (The chick down on recessive white...