It sounds like the DOC employees were at a different execution than the witnesses

Whether Diaz felt pain is important. If he did, his death could have violated the U.S. Constitution's prohibition against cruel and unusual punishment.

Department of Corrections Secretary James McDonough said all members of the execution team who were in the room with Diaz have indicated that Diaz did not appear to be in pain and went to sleep.
"There was no moaning, no groaning," McDonough said. "All the indications were a man at rest."

But several observers in a witness room, including a St. Petersburg Times reporter, saw Diaz grimace, squint, wince and cough for 24 minutes before he became still.

"It sounds like the DOC employees were at a different execution than the witnesses," said veteran death penalty lawyer Martin McClain.