i'm not trying to slag OP at all. i'm just wondering what happens when someone steals bitcoin, and then pays it back at a later date.
Don't steal from people and you will avoid these sorts of complications.
i've seen a few threads where people have paid back the old USD equivalent, rather than the BTC. but it's interesting that there still is no consensus (but lively discussion) on the issue of repayment even within the cryptocoin community.