When a purchase receipt has been matched to an AP invoice, to do the purchase return doesn't need to reverse AP invoice?

CASE:

A purchase receipt #66 has been matched to an invoice #77, when I do the return for this purchase receipt, Acumatica generated a return #88 directly, Acumatica doesn’t require the matched invoice #77 to be reversed. So in the end, I returned the goods to the vendor through purchase return #88, but I can still pay the invoice #77 to vendor. This is very dangerous.

Also if I don’t reverse invoice #77 and do the purchase return #88, GRNI account will not be correct, it has two debit amount, one from invoice #77 and the other from purchase return #88.

Any comments or experience why Acumatica doesn’t force the matched AP invoice to be reversed before doing the associated purchase return? 

Thanks!