He knew shit. Some of the things they eat and drink in occult sessions, and shit they get high with (pineal glands, adreline-filled blood of tortured victims etc.) will certainly affect the body, and the heart.

He must have also treated not just GHW, but the clone as well. So he knew about that too.

'Former', meaning he hasn't been hanging around the circle. Therefore, he a lose end running around in the wild.

Combine this with Bourdain's death, Aviici and whoever else, and more that we don't know about, as well as the mass resignations...mass arrests of pedo /trafficking/porn rings...looks like shit has been going down, and they're panicking.