By the 1960s, ordinary commercial firecracker explosives and gunpowder were two different formulations, and did not smell the same.
That many vets and police officers smelled gunsmoke in the GK area, in the immediate aftermath of the JFKA, has never been explained.
We know from women's coats and skirts that the wind was blowing towards the TSBD from the Third St. Overpass at the time of the JFKA---in other words, LHO and the TSBD6 sniper nest were downwind from the limo.
This, beyond dispute, rules out the TSBD6 location as the source of that gunsmoke.
Many ear-witnesses thought the shots had come from the GK, and smoke in the GK was seen by Sam Holland, a credible witness.
This is the same area where someone flashed an ersatz Secret Service badge at DPD Officer Joe Smith, also in the immediate aftermath of the JFKA.
Putting on a detective hat, one plausible explanation is that someone fired a handgun, possibly an easily concealed snub-nose .38 (the default concealed weapon of the time), as the presidential limo passed.
And indeed, the second official investigation in the JFKA, the HSCA-1979, concluded there had been a gunshot at the GK during the JFKA.
Caveat emptor, and draw your own conclusions. Your conjecture will be as good as anyone else's.
