Nope, he had been around for a long time talking about the case. Interesting thing is that he ending up backing away a bit from some of the more dramatic events of the "real life exorcist case" before he died. Strange Magazine did a good expose on the whole affair if any W's are interested.
Sad news. Sir Peter was a class act and a genuine talent. He was my favourite Poirot, as well. And as a raconteur, he was always one of the best interviews in show business. Here's one for his fans: http://www.durham21.co.uk/ archive/archive.asp?ID=918