No. They only took into account the machines' first 30 days of service life:

"we only count failures within the first 30 days of TACT (total accumulated computing time), for machines with at least 30 days of TACT."

That's an interesting point. Laptops get replaced faster, and when a laptop is replaced, it is typically left in a non-running state in which it will not experience or report errors. Desktops are often left running for months or years after they've been replaced, either through laziness or because of a desire to keep them around for a special purpose.