The only reason you know Cassiel was drugged is because you know spoilers. Jayne is not a fucking reader or omnipotent narrator, HOW the FUCK is she supposed to know? Too many retards saying she is blaming him for something out of his control when she is not an esper.

The author just wants her to hate him for his betrayal. Even though her friend Louise "betrayed" her pretty badly in the last timeline too. 

