The data in question dates from the 1980s. You couldn't "walk down to the local store and buy an external hard drive", and if you could a gigabyte of storage would cost you tens of thousands of pounds. Google didn't exist.
FTA: "Jones was not in charge of the CRU when the data were thrown away in the 1980s". What part of that makes it sound like this data was lost more recently than the 1980s?