That's a pretty big number, I'd question the accuracy too.
Thing is... I don't think it's off. I even did a rudimentary test last night where I simply spread my thumb and index finger to the center of my eyes, and then measured the distance. Given that human digit measuring isn't exactly very precise, it wasn't surprising to see that I came up with somewhere around 75mm with.... I'd say +/- 5mm variance. You may think, "Wow... that's really long", but there are 25.4mm per inch, which means we're talking slightly less than 3 inches.
I also just ran another test with a metric ruler where I kept one finger at 0 and moved the ruler to position the stationary finger (at the 0) in the center of one eye and shifted the other finger around. Same as before... it was at about 75mm. It might also be more believable if I said that I seem to have a big head, which is why I think that I can't wear normal hats. I have to buy XXL hats, and even those are kind of tight.