Probably the M64 of some dash variant. As for Glocks of the Mid 80s, that was when they were at their best. The first couple generations of their 9mms were just outstanding. They've gone through some ups and downs in design and QC since then.
The story does not make sense. I think what was really meant is a magazine disconnect, so the pistol cannot be fired without a magazine fully inserted. I don't think that is generally available on the M&P line, but I can't recall. Much as I find responding to public records requests a pain, this story shows what happens when public records law are weak. I can't tell beans about what's going on, and this is a big deal.
I agree with ATF, that generally there should be an approved list and an allowance, with cops getting what they want to use. There are specs on which I would insist, of course, but the silly uniformity/appearance fetish of some agencies, and state agencies tend to be the worst and completely out of control, is simply unacceptable. I can say confidently that although I think the .40S&W is over rated at best, if I were to have to carry for some reason, the M&P would be the first choice by a long way. I don't recall ever hearing of a generalized set of problems with them from anyone.