Well, the Bible *does* in fact have that bad awful definition of murder that it only counts as bad when it's against one's own group, as evidenced by the same god that ordered his people not to murder ALSO ordering them to go off and kill the neighboring tribes and take their land.
Thankfully, we've gotten better as a species since then and no longer use that as our definition.
The claim that the Bible has this horrid rule is true. The error is in thinking one should follow a horrid rule just because its Biblical. The rules in the BIble are just a record of what our ancient ancestors used to think was good. Nothing more, nothing less.
I get annoyed with fundies who want us to follow such horrible rules but also get annoyed to a lesser extent with nicer Christians in modern times who engage in a bit of historical revisionism by pretending the horrible things the fundies find in the BIble aren't there. It's never "yes those horrible things are part of the religion's history but we don't follow them anymore and have re-interpreted it to be nicer", which would be the honest approach. Instead it's "no you fundies are reading it wrong and our modern interpretation is the originally intended one."
That revisionist history makes it hard to highlight the examples of why religion isn't such a good thing. People deny that such cases are in fact examples of people following the religion's writings.