Evidently so: New mechanistic findings indicate that addition of dialkyl trimethylsilyl phosphites to α,β‐unsaturated imines has been incorrectly reported as an exclusive 1,2‐addition. When α,β‐unsaturated imines are used as substrates, 1‐alkylamino 3‐phosphonyl phosphonates are formed in high yields in the presence of a suitable proton source through a sequential 1,4‐ and 1,2‐addition.