IIRC the amphetamine is from weight loss pills. Not like she was a meth addict tweeker under the influence. I’m sure if I took a blood test I’d pop positive for amphetamines as well since I’m on Adderall. I disclose it on any dive medical release and keep a current doctor signed physical on file just in case, but I don’t think either drug she allegedly had in her system had any impact on the accident.
The best swimmer you know, 100% free of any kind of drugs in their system, is not going to out swim a 40’ boat in reverse. Add in all the gear, waves, and a boat backing down on you and none of us would have stood a chance.