MTG-
Yes, the consensus, as seen in a credible recorded witness such as Bowers, is that the last two shots were in rapid succession.
As the TSBD sniper (I suspect it was LHO) was armed with a single-shot-per-bolt-action rifle, that is one reason that the LNT is implausible.
There are other reasons, such the scent of gunsmoke in GK area in the immediate aftermath of the JFKA, Sam Holland's account with visible gunsmoke in the GK, and Gov. JBC's testimony that he was struck by a separate shot from the one that struck JFK, testimony with which his wife concurred.
I have never been able to make head-nor-tails out of the acoustic evidence.
However, Blakey of the HSCA said the acoustics evidence was only one factor in their estimation that there was a probability of a JFKAC, and of a gunshot from the GK.
We disagree on the extent of the JFKAC, and that is fine. I suspect small conspiracy of anti- or pro-Castro Cubans who worked with or manipulated LHO. Maybe just two other people.
But that's just my IMHO. Caveat emptor, and draw your own conclusions.