Yes, this doesn’t make sense to me neither.
I suppose on the retweeted tweet info you would only have to see its own favorites and retweets. Something like this:
Original tweet
“retweet_count” => 36
"favorite_count" => 12
Retweeted tweet
“retweet_count” => 1
"favorite_count" => 2
But if not, at least be consistent. Either they are the number of retweets and favorites from the original tweet or they are not.