The text: "The court determined that Student B exhibited adverse educational impact because notwithstanding her passing grades, during her final year at School #1, her symptoms were sufficiently severe that she was unable to attend public high school at all and required homebound instruction."
My analysis: The distortion is in the word "passing." Student B was actually earning all A's and B's. But the author of "the text" finds it expedient to call the grades "passing" because elsewhere in her document she argues that Student A did not experience a significant academic decline when he went from a 3.8 gpa to a 2.2. So she harps on the fact that although Student A's grades have been declining, he is still passing his courses... and therefore should be found ineligible for special education.
A helpful ELU participant proposed the following description of what's going on:
When a fact is presented as representative of the truth, even though it clearly omits key details.
What is this rhetorical device called?
Bonus question: I also need an effective idiom or simile which describes this form of bias or slant.