Interesting. A decade ago I observed something similar to the article while traveling in Nepal / Tibet.

Me and friend both had iPods (of different generations) that got 'altitude sick'.

At two points in the trip we got about 5,000m. Each time both iPods went totally unresponsive. Both times we'd only be there for a few hours and once we descended they'd stay working again.

Obvious thing was something to do with the cold and battery, but both times the battery came at the same charged once they started working.

Can't remember exactly what the ambient temperature was (we were in cars both times) but it's puzzled me whether it was cold or altitude.