They could have possibly made all their requests within the rate limit imposed by Google. I'm unsure, however, if their usage of the data was allowed: "The Elevation API may only be used in conjunction with displaying results on a Google map; using elevation data without displaying a map for which elevation data was requested is prohibited." [1]

That said, I certainly think it's reasonable to want Google to allow paid access to their API at a rate between their current free offering and their prohibitively expensive offering for personal and small business usage.

[1] https://developers.google.com/maps/documentation/elevation/#...