>>But the key point is that it's used briefly and specifically to draw attention to an individual item.

Microsoft also causes a dialog to flash if you try to move focus back to the underlying app without closing the dialog. Flashing is acceptable as a cue for "you are here" rather than an attention-seeking device for a field or value.

I have no issue with medical apps flashing problematic readings either. Check out "the machine that goes ping" and the visual and aural cacophony it creates if it doesn't like a reading. Those machines cost a lot more than a PC and are designed to the nth degree to satisfy caregivers and avoid litigation, so IMHO their GUI decisions are just as relevant as those designed for office workers.