as far as i remember when he ws holding the lamp n searching in the ristricted area of the lib filch snape n quirrel werent there they appeared after the lamp ws broken harry heard filch's voice he grabbed his cloak n at tht moment the lamp fell n broke filch showed the broken lamp to snape so they didnt sw it in midair bt yeah it ws out of the cloak so may b cloak just covers/hides the witch or wizards nt the thgs