John in that moment has an idea occur to him. These two were already leaving with giving them nothing much incriminating or helpful in the matter of information to solving this case.
So how about he try out something daring and see how they react to it. Besides the damage has already been done, telling them about it would not make much of a difference but maybe only help them getting to the person who was behind last night's disastrous incident. Were it either one of them?
Leo is eager to save his girlfriend and it seems like Ivar wants it to be her; his attitude was proving to be suspicious. Leo may be out of suspicion but Ivar actually made himself a suspect in this session today with the way he was taking his own girlfriend's death in joke as if it didn't affect him at all, a behavior that could be taken as openly sociopathic or a disguised psychopathy.