IANAL, so take everything I say with a truck of salt. The DMCA requires that each takedown notice is made under penalty of perjury. However, the statement is

IANAL, so take everything I say with a truck of salt. The DMCA requires that each takedown notice is made under penalty of perjury. However, the statement is "I believe that this work infringes on my copyright." rather than "This work infringes on my copyright." So long as the person issuing the takedown notice believes that it is valid, there are no consequences.