The consequences of Ashing Reinforcement of the Army

I thought that was the right play. Nobody Ashes ROTA, and they still didn't know what I was playing, so surely they would let it resolve and I would get Razen, and from there it's game over
But instead, they Ash that, my Prosperity finds nothing, and we spend 16 turns topdecking. Hilariously, one of the better games against Lab I've played, if you ignore the Rivalry that somehow lasted nothing on the field
And you damn well know I was gonna BM the fuck out of my opponent once I had lethal. Which I missed a turn earlier, but it didn't matter, I was simply more skilled