The news is out, See:
Lowry was interviewed on Civil War Talk Radio in its early days; he uttered one of George Carlin's forbidden words IIRC, irking Gerald. I found him overconfident of his achievment, evasive, and without historiographic sense.
I read at least three of his books (see here, here, here). He was an author who consistently went farther than the material allowed.
It's not that he stretched the material, it's that he would pick his premise first - always from a dramatic marketing angle - then marshal the supporting data which would fail to measure up to marketing's promise. We're talking undergraduate history papers.
Lowry is an enthusiast with focus on the wrong things. He is a sensationalist. I think he could make himself useful as a compiler of information rather than as a narrative historian. That would be a better use of his energy, if he has any left after this scandal, and if anyone will trust such compilations.