I work in medicine, where we perform tests that are sometimes inaccurate, and at times you get clues that the result of your test is inaccurate.
I recently heard an expression using "given" that I don't understand: "given A, the result is B." A is a phrase arguing that the test result will be inaccurate. B is the result of the test.
In case that's not clear, here's an example: "given that the xray is misexposed, there is no pneumonia."
This strikes me as very wrong. I'm used to using "given A, B" to mean "if you take A to be true, B must be true." In the usage that I believe to be incorrect, on the other hand, it means "take B to be true with the caveat that A is true (so the validity of B should be discounted)."
I would have assumed those people were just misusing the word, but I found this example at the Cambridge English Dictionary: "Given his age, he is in good health." That feels sort of similar (but not identical) to the usage that I thought was incorrect.
Has anyone heard this usage? Care to give an opinion on its validity?