Most likely, a named (female) variety was grafted to male seedling rootstock, which is perfectly acceptable practice, but then the graft failed and the male seedling grew out. You bought the male tree, labeled Yates (or whatever).
Well I bought the scion from Cliff England. It was quality stuff. I grafted it, but then I left for a 4 day rafting trip in the desert. No water for 4 days in a hot spring. Sadly, it appears that none of the grafts took. It was a great rafting trip though.
However, I have been checking and I have a lot of fruit! I am growing Yates, Early Golden, H-118 and Garretson. Many of them are descendants of the varieties that sometimes produce male flowers at times. Maybe the rafting trip was more important than the new varieties.