Sure. But Russians are notorious for various things - being blunt and serious; depressive, black humor; risk-takers. Not everybody, but the stereotype can inform the discussion, which was Why would anybody do this?

It seems that this stereotype is too generic and sweeping to be useful even if it was true.

Instead we could use facts that are already known about e.g. Putin -- that he's an individual for whom sowing fear is more important than not being blamed, as the other similar poisonings have shown.