I can't really remember where I read this - could be Jim Marrs's Crossfire or Mark Lane's Plausible Denial, but I do seem to remember speculation that the hospital staff administered injections to Ruby containing cancerous chemicals. This ties in somewhat with Judith Vary Baker's story of a CIA-sponsored programme to develop a cancer virus to be injected into Castro, a project Oswald allegedly assisted in New Orleans in the summer of 1963.

I'm in agreement, DC. The Warren Commission's version of events vs the eyewitness accounts, medical and forensic expertise, physical evidence and, of course, the Zapruder film... there's no contest which is more plausible.