A bullet that nicks a window frame "logically" suggests the gunman was trying to miss and the attempt was staged? There would be 100 ways to miss, but the gunman zeroed in on the edge of a window frame? This is Conspiracy Logic 101, a/k/a Alice In Wonderland logic, a/k/a Anti-Logic.
I waded through Gerg Doudna's Walker scenario just as I waded through his Tippit scenario. It is a clever but completely preposterous effort by someone almost pathethically desperate to make a mark in JFKA research. I believe it might have been Kevin Balch who characterized his Tippit effort as an "off-Broadway production" - i.e., an entire cast of not very talented actors with a not very believable script.