SGtools' "You must not have won a game multiple times" meaning?

There is a setting to hide games you own on steam. That would be people who A) Don't hide games they own, or B) won a game and didn't claim it on their account.

This was a more frequent occurrence a few years ago - people could, for example, enter two giveaways for the same game that end at different times, win the first giveaway, then win the second, and claim both/mark both as received. Nowadays there are additional measures in place, for example, winning a giveaway for a game automatically removes your entries from other giveaways for the same game. With that said, other factors such as API issues with certain games/packages would allow users to enter giveaways for games they already own.

Claiming more than one of the same game in giveaways on SG is against the rules, but similarly to unactivated wins, could go under the radar. This requirement in SGTools aims to catch these situations.