That's not the thing, Marcel. Regardless of what the meter is suggesting as the proper exposure, the exposure settings should fall within those specified in the Auto ISO settings. If he has a minimum Shutter Speed set to 1/125sec then it shouldn't drop below that without hitting the Maximum ISO setting first (in this case 3200). With those parameters set and Auto ISO turned on it should be impossible to get a shot at 1/40, f8 and ISO 400 in Aperture Priority mode.
If I remember correctly, the meter will overcome the limits and the shutter speed could go lower BUT when it does that, the display turns to RED in the viewfinder. Now I'm not 100% certain and don't have the time to check this morning, but I think this is what happens when you run out of enough light.