Confession time.
After more than 25 years of designing embedded systems, I too, on occasion, miss a nugget of gold in the data sheet due to skimpy reading.
The thing is that no one, OK make that very few, can retain all information in todays 100 page datasheets. The thing I (and I presume others) goof on is, just like Jez, when a problem is seen, we should read the relevant pages of the datasheet again.

Erik