Not one post in this thread addresses the reason for Cam's difficulties since the 27:07. Let's review, shall we?
In 2015 he fell at the end of a 1500m heat at Nationals. This fall caused a lot of ankle problems which were not diagnosed properly until much later. (There's a good story about NOP negligence/incompetence here, but we'll leave that for another day.)
After a year of struggles things finally came to a head exactly one year later (July 2016) at the same venue: He limped home in the 5000m, needed to be on crutches, was properly diagnosed, then had an operation.
It took a LOT of time to ease into training again, and to make the ankle happy.
He recently ran a 65min Half that hardly anyone knows about.