To begin with, Rowland wasn't "mercilessly grilled." He was questioned with about the same intensity as any of the other witnesses. That being said, Rowland isn't "a threat" to anything but verisimilitude.
Initially, I didn't have an issue with what Rowland said. Then again, I was relying on the story second hand, only taking in what different authors had to say on the matter.
Then I actually bothered to read Rowland's testimony. On his own, he raised a number of red flags. His claims: to have super human vision, to have conducted fairly advance experiments in gunfire acoustics, to be taking "post-graduate" classes at a local high school, 147 IQ etc, etc, stretched credulity to the limit. I then read his wife's testimony. Her word deflated his puffery: he wasn't a straight "a" student, by any means. He hadn't graduated from high school, as he'd claimed. In fact, her testimony gives the impression that she really didn't believe him, either in as to the "gunman", or just in general. There were no special lesions or experiments in echo acoustics (for that matter, Rowland failed his basic physics class).
Rowland's statements raised the same red flags with the WC staff that it did for me. A few days after his deposition, they asked for a background check to be run against the various claims he'd made about himself. The result is interesting reading, to say the least. None of his grandiose claims were true. Once the balloon had been punctured, it shriveled into the shape of a big dreamer was was noting more than an itinerant high school dropout. A young man who flitted from school to school after wearing out his welcome, who did the same from job to job and from one domicile to another. A young man whom others had learned not to believe long before November 22.
The biggest issue I have is, someone who wishes to assassinate the President is not going stand up and proudly show off his rifle to everyone in Dealey Plaza 15 minutes before the act. After all, the first rule of covert action club is to keep the action covert. And, there is the way the gunman starts out 15 feet behind the window, then systematically moves closer and closer once Rowland realizes that someone so far inside the building would be lost in the shadows. Then he tries to come back in the WC deposition and claim that he didn't say the rifle guy was that far back. I guess he forgot he said differently, first to the Dallas Sheriff's Department, then to the FBI. There is the mysterious, late appearance of the "elderly negro," who only appears in his WC deposition. I know that a lot of people want to believe that this man was Bonnie Ray Williams, but Williams was only 20 in 1963. How did he age so fast? Nessan also has a good point about Rowland's description of the bottom of the window appearing to be 18" above the rifle guy's head. Given the low window sill, and the limited height the sash could be raised, Rowland's description is best described as, "impossible".
You are a believer in the Miracle On Elm Street.
Arnold Rowland describes a man on the 6th floor of the TSBD carrying a high-powered, scoped rifle.
He describes the man as a white male, slender in proportion to his size, short hair, wearing a white/light coloured open-necked shirt.
Ronald Fischer describes a white male, slender, short hair, wearing a white/light coloured open-necked shirt.
Robert Edwards describes a white male, slender, wearing a white/light coloured open-necked shirt.
Howard Brennan describes a white male, slender, short hair, wearing a light coloured/dingy white shirt.
Wow Mr Rowland! Take a bow.
By some incredible coincidence you've managed to describe the man in a way totally consistent with other witnesses.
If you were making up a Secret Service Agent, why not have him in a black suit?
Barbara Rowland reports that Arnold told her about the man with the rifle before the assassination.
Roger Craig reports Rowland telling him about a man with a rifle on the 6th floor of the TSBD.
As does D V Harkness.
As does F M Turner.
As does Forest V Sorrels.
So, you believe that Arnold Rowland is running around telling everyone he can that there was a man on the 6th floor with a scoped rifle and that this was just a figment of his imagination and that it was just some unbelievably miraculous coincidence that there was indeed a white male, slender, short hair, wearing a light coloured/white open-necked shirt carrying a high-powered, scoped rifle on the 6th floor of the TSBD?
Not the 5th floor.
Or the fourth floor.
Have a think about that.
You believe that Rowland just happened to describe, by sheer luck, a man with a rifle
on the 6th floor of the TSBD, whose description perfectly fits that of other witnesses!
Is that what you actually believe?