Playing devil's advocate here. How much change in the design would people think it is not a rip-off? If they changed the color scheme? If they changed the font? The type of visualization shown seems pretty standard (looks like a treemap plot?). I don't want to denigrate the importance of stylistic choices as they are very important in data visualizations, but it seems like a pretty standard visualization.

Perhaps it is the dimensions they chose to represent out of the data that was a rip-off? Ripping off methods of visualizing subtle aspects of the data that conveys information would be a more egregious offense to me.