Do you have any valid references for that assertion?
A cursory search on Google shows only current posts with suppositions and assertions but without references to historical documentation.
Either there are no earlier references or no one has gotten around to planting them yet.
I’m way late to this thread and maybe it’s been posted, but I read on another thread that Breitbart’s FIL, when the heart problem issue was mentioned, knew nothing of any previous or recent heart problems. You’d think he’d know if his daughter’s husband had serious health problems or any kind of heart problems.