Hi soda,
rather than explain I will quote Robert's Rules of Poker (RROP):
15. If the dealer prematurely deals any cards before the betting is complete, those cards will not play, even if a player who has not acted decides to fold.
16. If the dealer fails to burn a card or burns more than one card, the error should be corrected if discovered before betting action has started for that round. Once action has been taken on a boardcard, the card must stand. Whether the error is able to be corrected or not, subsequent cards dealt should be those that would have come if no error had occurred. For example, if two cards were burned, one of the cards should be put back on the deck and used for the burncard on the next round. On the last round, if there was no betting because a player was all-in, the error should be corrected if discovered before the pot has been awarded, provided the deck stub, boardcards, and burncards are all sufficiently intact to determine the proper replacement card.
17. If the deck stub gets fouled for some reason, such as the dealer believing the deal is over and dropping the deck, the deal must still be played out, and the deck reconstituted in as fair a way as possible.
so for example: The flop is dealt too early by dealer error, so the burn cards are issued for the turn and river along with the turn and river cards face down before the existing flop is reshuffled back into the stub and a new flop is issued without burning cards, the turn and river can be turned over when required.
I hope that answers your question correctly.
Best Regards
Stuart