I don't know anything more about this than you guys do. This is not off topic at all. But, I recall that the video of the tsunami arriving at, I think, Thailand resort showed a very large wave height; it may have had a bit of a curl to it. The NW coast of Sumatra was much closer to the large fault slips. Offshore bathymetry would logically focus and unfocus the tsunamic waves (liek Jaws on Mauii). So, yes, it sounds like they are measuring runup heights, but I would not rule out 30 m crest to trough waves in some locations. Just my best guess.
Chris