"Not received" for old winnings?

Giveaway makers have 7 days to give you the game. Has it been 7 days yet? If not, you won't be able to mark it not received. Also, the reason you can set it as not received for old winnings is in case of revocation etc.

The creator has 7 days to deliver your gift, that's why you have 7 days delay before marking it as not received. And also gifts can be revoked after some time due to fraud payment methods, etc so you have the ability to mark it as not received if this happens to you.

Works as intended, guess it's that way to prevent abuse and to open some sort of possibility of appeal for older winnings if the game gets revoked for whatever reason.

Actually if you search for the word days in Terms of Service (link in the bottom right corner of any SG page), you will see the 7-days term, and it also appears in the FAQ page (direct link above, but if you open any of the two, there will be navigation between the two pages on the left)

Okay... but if this is a reason then assuming the user marks a giveaway as Received prematurely, he/she cannot change it to Not received for 7 days. Wouldn't it make more sense to just not take Not received markings into account (in regards of profile's score) for 7 days instead?

There are three states:
Neither Received nor Not Received (null)
Received
Not Received

If you accidentally mark something as Received, you can unmark it as Received, returning it to the null state.

You can set it to not received indefinitely. This is there to make sure that if a game was bought with a stolen credit card and later revoked, you can unmark it.

Which is a very nice notion, but in reality it is more commonly used by regifters, key stealers, resellers, and other assorted nice people to mask them stealing the key when they are faced with their first SGTools-protected giveaways. Resulting in an endless battle with Support, supplying evidence that the key was sent and received normally, dear user just tries to be a clever asshole instead of a normal asshole.

This is why I really wished that the button would lock into place 14 days after pressing it as received and winners asking support with a nice picture proof of game removal to forcefully set it to non-received. I swear the amount of those tickets wouldn't be a percent of the current request feedback ones.