No mention has been made of the time this event occurred. If they were at the end of an all night flight, I wonder how much fatigue may have contributed to this event.
The AAIB report states the incident happened at 16:10 UTC (so 17:10 local) after a return flight to the Canaries from Newcastle. Mid August so daylight. Weather reasonably benign.
Arguably, the situation began to develop before the G/A when the crew failed to capture the ILS localiser at first attempt. As a non pilot it's not 100% clear to me why, but the report suggests high speed was a factor - perhaps they should have had a few more track miles to lose the excess knots?
For whatever reason the Captain was, from that point on, developing a thought that there was something wrong with the aircraft.
Was that the first 'hole in the cheese'?