I think there are multiple issues being conflated here. Yes, apitrace had some bugs, and they might have cause additional grief to Mesa drivers when replaying traces from XCOM. But if the question is "does XCOM have a bug?", then the answer is IMO a definite "yes". As explained in https://github.com/apitrace/apitrace/issues/407#issuecomment-166619366 the game is passing indices outside start..end range, which is illegal per https://www.opengl.org/sdk/docs/man/html/glDrawRangeElementsBaseVertex.xhtml "all values in the array indices must lie between start and end, inclusive, prior to adding basevertex". So if the XCOM developers are looking at this bug report, then please fix this issue. Even if it's not the all story here, it is a bug on its own right, which can and will cause rendering issues depending on the OpenGL driver implementation.