She didn’t say how many, specifically. She said that it looks as if he might fail 2 or 3 classes. It might still be possible to salvage two of his presumably 4 classes, and take two incompletes, and finish them over the summer, what with the parental support he could receive at home.
But yes, it can definitely be a bear of a situation struggling to get an oppositional teen to finish up the incompletes! But it might be a better option than withdrawal.