LOL at last, someone figured it out.
Seriously saying good morning last I heard was not blasphemy, sinful, nor disrespectful, to anyone including The Lord in any church.
It's my understanding that "good morning" (no matter how innocuous) constitutes a "deviation from the script" that directs how mass should be conducted, and deviations are strictly forbidden. The way this story is being reported, it sounds like being friendly is also being forbidden, hence the "Walter" impersonation.
I reckon saying Shalom{sp} would spark a riot??? I'm not RC. In the church I went to the Minister of Music began the service with the choir singing then next three songs congregation sang. Then the preacher stepped up and said Let us pray then followed by prayer amen "please be seated" a welcome to ones there, followed by scripture passage, then any announcements etc. Then another song then the sermon, Alter Call, and dismissal song and a prayer used done by an elder.