I know red water is incomplete but when it is in a buildcraft quarry, the quarry will repeatedly try to break the moving red water block as well as the source. I think it has to be added to the Boolean softBlocks array in the buildcraft api.

Thanks for the report, but declining the PR on the basis that Red Water is not finished yet and thus it's not proper to apply a fix for another mod when it doesn't even work properly in this mod. Thanks for the effort though!!!