this person wasn't 'blaming' the drugs for bad behaviour, merely commenting on some of the side effects, which mind you, does not demonstrate 'extremely limited' understanding as you put it.
I have worked in this field and it is fact that people who abuse ice can become more agitated, aggressive, violent, and indeed, suffer from psychosis.
NONE of these side effects excuse this monster's behaviour even if he did take it. He has been a sexual predator since he was a teenager. Even if he had been abusing ice for every assault, it would not be the drugs fault!!! In fact, it would make any reasonable person stop/find alternate ways of coping so as to prevent harm to others.
Separate to discussing this monster, it is however fact, that the additional use of ice for creatures like AEB can create agitated/aggressive responses on top of their already inhumane violent behaviour which AEB was unwilling to change with or without drugs being brought into it.
See below ice information; it's not really fair to label someone as having 'limited understanding' just because their opinion is different to your own.
http://www.druginfo.adf.org.au/drug-facts/ice
High doses of ice can intensify some of the effects. People may also experience:
blurred vision
tremors
irregular breathing
loss of coordination
collapse
rapid pounding heart
violent or aggressive behaviour
hallucinations.
'Ice psychosis' is caused by high doses and frequent heavy use. It is characterised by paranoid delusions, hallucinations and bizarre, aggressive or violent behaviour. These symptoms usually disappear a few days after the person stops using ice.
Low to moderate doses:
feelings of euphoria, excitement and a sense of wellbeing
feelings of confidence and motivation
sense of power and superiority over others
increased talkativeness
increased libido
restlessness, repeating simple acts
nervousness, anxiety, agitation and panic
paranoia
hallucinations
irritability, hostility and aggression