Safe to ask for replacement item?

[gorbasho]

I bought an item recently that was damaged in shipping due to poor packaging by the seller. I opened a case and the seller says that if I send it back to him he may potentially be able to get me a replacement, otherwise he will refund me. My question is whether it is safe to accept the replacement, given the unusual situation of "maybe replacement, otherwise refund". As far as I know the options provided by eBay are keeping the item for a partial refund and returning the item for a full refund. I want to make sure that sending a replacement would be covered by the buyer protection system, ie he is required to send a replacement within X days of receiving the original item back, required to upload a new tracking number, etc. It would be easier to get a replacement rather than me returning it and having to go find a new item elsewhere, but it seems like there is the potential for headaches if he decides not to ship a replacement or if it arrives damaged again.

[gorbasho]

Well I guess I'm just unfamiliar with the system, upon reading more on how it works it seems replacements are fairly standard, so I guess I'll go through with that.