Microwaving Good-bye

I'm a bit confused. A reportedly vulnerable woman has apparently been given a 14 week jail sentence for putting her kitten in the microwave, causing 'horrendous suffering' when she believed it had killed her pet goldfish. She has (in my opinion, rightly) been banned from keeping animals for an extended period. The reason I am confused is that I believe that killing of experimental animals with microwaves has been an approved method used by some neurochemists because it supposedly produces an immediate destruction of the proteinaceous enzymes that destroy neurotransmitters (the chemicals that allow nerve impulses to cross the gaps between nerve cells). This enables them to measure levels of neurotransmitter with no post-mortem loss of material.  The method is supposed to produce an immediate loss of consciousness.