Spreading of rumors and suspicion as done by ExbethelitenowPIMA is disgusting.
Obviously, something serious happened, or was happening, for AM3 to no longer be on the GB. Based on what people know about him, alcohol abuse related to his PTSD would be a good candidate. This "educated guess" is indeed plausible. In the absence of being told anything at all by the Watchtower, I believe that JW and xJW alike are entitled to venture into such "educated guesses".
Of course, to say that he "touched his daughter in law inappropriately" makes it sound like he got sexual gratification out of it, and quite frankly, I find the idea repulsive. There is nothing in that man character that lends credence to it. However, if he did something like that, it was probably a "Holy Shit, I thought you were my wife! Oh my God! SO SO SORRY!" moment. I've seen that happen and people generally understand it to be poor eyesight or drinking problem; not "He's a sexual predator".