Haven't finished it yet but so far mistakes include:-
Both Harry and Sebastian going to deliver their readings at a funeral at the end of 'Abide With Me'
The hospital chairman being called Nick Caldercroft at one point then Nick Croft later on.
Giles proposing a new chairman then the company secretary asking if anyone else would second 'Mr Clifton's' proposal.
Sebastian booking and taking a taxi to the Mayflower hotel but checking into the Willard.
It's hugely frustrating. That and the fact the plot is very thin, some of the sub stories are completely unrealistic and Sebastian's daughters language/ actions are totally unbelievable for a 10 year old.