Ah, then they are calibrating their CGM (likely integrated into the pump, as they are likely using either an Animas Vibe (outside the US) or a Metronic Minimed Paradigm). They aren't calibrating the pump, they are calibrating the pump's CGM vis a vi their meter via finger stick.

Not an expert, but maybe he's talking about the relative changing the basal rate (correct words? The 'give me this amount continuously' rate a pump will inject) or (this is something my type I ex-gf did a lot) he mistakes some 'correction shots' after meals for calibration?

Definitely involves blood and a small oval thing with a LCD screen.