The core meaning is clear. When used in a scientific discussion, especially a speculative one, it is understood to mean "does not disagree with" rather than actively agrees. I don't think there's any excuse for "bristling".
I'd disagree with what you determine to be "clear," especially when the users of the language seem to be insisting on casual understandings and interpretations rather than employing stricter, and more proper scientific qualifications, only begrudgingly acknowledge the range of actual science evidences when dragged to them, and then use such casually misstated arguments in the support of assertions that are quite simply unsupported by the evidences (eg "Evidence for ET is mounting daily"). The word doesn't cause "bristling," the repeated and continuing context of its misusage and misapplication can, however, have that effect on some people.