"If I put the purchases of hundreds or thousands of them in chronological order, then found 4 in a row that had failed, it wouldn't mean much (like the Aces example)."

But this is exactly what happened to your friend. You can't ignore the thousands of other Macbooks that were sold to calculate one number, but then try to apply that rate to those thousands.

"If I have a sample of only 4, and 3 failed, that means quite a bit more."

That means quite a bit more for that specific sample of 4 Macbooks - but no one cares about the failure rate for your 4 specific Macbooks. You proved that failure rate for those 4 Macbooks was exactly 75%. Nothing more, nothing less.