Really, having set secveral hundred toilets over my career, I am having trouble figuring out how the guy before you managed to do that.
But, at least they used a wax ring.
I did one a while back on a 9 year old house. The plumber had completely forgotten to use a wax ring, but did a VERY good job grouting the toilet down. It had finally started seeping, and when I broke the water closet loose, a tidal wave of black "water" flooded the toilet room.