To make blockchain more forgiving for human errors it's time to introduce the "undo" transaction.
This undo transaction can be issued up to 5 blocks from the original transaction, after which it is no longer possible.
In case of bitcoin this should give the user 50 minutes the time to issue the undo transaction, after the 6th confirmation of the original transaction it is no longer possible if the undo transaction was not included in the 2th, 3th, 4th, 5th, 6th block since the original transaction, being the 1th block.
First clarification is 50minutes doesn’t mean your transaction will be in the 5th block already. Yes the average time to mine a block is ten minutes but that is not constant and it varies, you can still be have one single block mined in whole 50 minutes.
Now base on your question, I think undo transaction can lead to double spending which will be a very bad flaw if a blockchain has it, take for example bitcoin Been treated as means for payment and when the payment is done imagine the sender going behind to double spend such transaction what happens to the seller who got double played will they use bitcoin as means of payment again? Even traditional banks don’t release wrong transactions immediately they check to see if it was genuine mistake before they process the reversal. So undo transaction isn’t a good move to me