Zevachim 46 - Exceptions to the Exceptions for the Laws of Rejection
We have learned that the law of rejection is not applicable to some substances . For example, the blood of the sacrifice itself (the "permitter") does not becomes rejected even if the kohen had the wrong, "beyond allotted time," intent. However, these substances may carry other penalties.
The blood is forbidden to be consumed in any case. Furthermore, one is liable if he eats the substances as "leftovers" or if he eats them while being ritually impure, and for that he still gets the penalty of being cut off from the people. "Leftovers" designate any sacrifice that is eaten beyond its allotted time. Consuming blood is also forbidden under the penalty of being cut off, but one does not get an additional penalty if he eats it as "leftovers" or while being impure.
What is the practical difference? One is "cut off" from Heaven, thus, being "cut off" more than once is left to Heaven to decide. However, if one, for example, eats blood inadvertently, he is liable to bring a sin-offering, and there may be more than one sin-offering, if he commits a transgression bearing multiple penalties.
Art: Henri Matisse - Dinner Table