The only read of this CNN report from Jim Acosta on the 25th Amendment is that what's keeping Pence from invoking it now is that he and those close to him fear it would "risk...provoking action" by the president, which if it isn't a reference to civil war I don't know what it is.

(PS) CNN attributes this to "a source close to" Pence, and underscores that the 25th hasn't been taken off the table. But what "action" could Pence's team fear Trump would take, if he'd just been removed from office? Incitement of further insurrection is the only possible answer.