2x metformin

my mother died Oct. 6th 2013. 2 years prior was perscribed 2x the normal dose of metformin, trying to boost it into her system, attempting to keep her off insulin, she was 12 days away from 70. Her Dr. died unexspectantly, before reducing the dose. the doctor that picked up her case didnt notice that it was 2x amount, without even seeing her, just kept rewriting perscript. the pharmacy didnt catch it either, 2 years later she is admitted into hospital with urinary trac infection, 6 days later she is unresponsive, being released to hospice house, she passed less than 24 hrs later. my question, could 2x max dose metformin for 2 years cause her liver to become saturated with non alcoholic serossis of the liver and kidney failure?