It was easy to distinguish an altered memory from a true memory. That had been a valuable lesson she had to learn early on in her career as an interrogator. As the scene of their bedroom came into view, Hermione knew without a doubt that Antonin was showing her the truth. There was no haze clouding the scene as it had when she first watched her memory of Andromeda's murder thanks to the potions blocking her recollections. There also didn't exist the choppy breaks that a trained eye could see in a manufactured memory. Whatever she was about to witness was exactly what Antonin saw that day.