If you ignore the evidence outside molecular signature yes, the “Moon of Alabama” hypothesis sounds plausible. Given the facts and circumstances, however, the conclusion becomes unavoidable.
The circumstances are that an english-tweeting western-sponsored Yale World Fellow with approximately zero actual Russian support found himself "poisoned" (nonfatally, of course) in a way politically useful to the west in their ongoing project of destabilizing Russia, as diagnosed by western security services.