Google Earth must be way off, at least the measuring tool. I used a different calculator, it says 2561 sm.
This is a point 41 sm past Howland according to Google Earth, this cannot be correct then.
I get very good accuracy using the Google Earth measuring tool so you may be doing something wrong.
You can avoid all of this by just doing the trig yourself, just use the standard formula for great circle distance.
Great Circle Distance (NM) = 60 X arc cos[ (sin LAT1 x sin LAT2) + (cos LAT1 x cos LAT2 x cos(difference in longitude))]
To find the difference in longitude, if they both have the same name, east or west, just subtract the smaller from the larger. If of different names then add them together. If the total is greater than 180 degrees then subtract the result from 360 degrees.
The coordinates used by Williams were 6° 47' S, 147° 00' E for Lae and 00° 49' N, 176° 43' W for Howland.
To find the distance in statute miles simply multiply the above result by 1.15.
gl
I have attached Williams' Honolulu to Lae strip chart.