just finished jfa case 2

So there's this thing I don't really understand when it comes to which costume was burned in the incinerator. I believe it was Mimi Miney who changed Maya's clothes right? Mimi stabbed Grey and the blood got on her costume, so Mimi let Maya wear her costume, and then burned the one she switched out. This all happened after Morgan chased Wright and Lotta out of the Channeling Chamber. The thing is, it was believed that the bullet went through Maya's sleeve when she was in the box. So if Mimi let Maya wear he costume, that means Mimi burnt the costume with the hole in it. So how come the evidence submitted had blood and a bullet hole in it.