Norman Tebbit has expressed his support for Whitelaw's decision not to allow the police to pursue Father Chesney properly (but at a higher price) and repeating the civil war defence as an excuse. There seems to be scant evidence to support this claim rather it looks like a rationalisation developed now with a mainland audience in mind - the "It's Northern Ireland what can you do" option. Other priests were arrested and prosecuted for terrorist involvement without civil war breaking out. Also in 1972 sectarian tit-for-tat needed nothing to encourage it. It was already in full flow with no shortage of outrages for those seeking to forment civil war to cease upon.
The more likely explanation is the more calculating answer that the new Secretary of State wanted the Church in the position that it owed him a favour. However, barefaced political calculation as a defence would have made the blowback from the Claudy report even worse.