By now, pretty much everyone has seen the finale of Game of Thrones Season 7. If you have not, the internet has comfortably updated you with everything. As much as everyone enjoyed the closing episode, a lot of us must have felt that Littlefinger's exposition scene was a little rushed, that it lacked background.

Source: WikiofThrones

The master schemer of the show, Petyr Baelish was taken down by the Stark kids and defeated at his own game. Inevitably, Sansa couldn't have seen through his ploy without the help of Bran, the three-eyed raven. From the moment Bran repeated the words, "Chaos is a ladder" we knew that Littlefinger's end is near. However, with his sharp wit and tongue, you couldn't really say. 

Source: IndieWire

Viewers were given no hint of any interaction amongst the Stark kids regarding Littlefinger before the scene at the Great Hall. However, in an interview to Variety, actor Isaac Hempstead Wright who plays Bran Stark in the show said:

"We actually did a scene that clearly got cut, a short scene with Sansa where she knocks on Bran's door and says, 'I need your help,' or something along those lines. So basically, as far as I know, the story was that it suddenly occurred to Sansa that she had a huge CCTV department at her discretion (The Three-Eyed Raven's memory) and it might be a good idea to check with him first before she guts her own sister. So she goes to Bran, and Bran tells her everything she needs to know, and she's like, 'Oh, shit." 

Well, we can totally understand why this might have been done. Such a scene would totally take away the surprise element of the trial and we wouldn't have been able to enjoy that shocked expression on Littlefinger's face just as much. Hempstead goes on to clarify that even if Sansa hadn't sought his advice, he would obviously have meddled in Arya's trial, but what fun would that be anyway.

Source: WikiofThrones
"It was a battle between Sansa and Arya really, and it wasn't any of Bran's business until Sansa thought 'why don't I fact check this with the best fact checker in the universe' and Bran was like 'Littlefinger did this and this and this. Because Bran has a real idea of destinies, I think he was waiting for his sister to come to him to give her the knowledge. I don't think he would have let that happen and he wouldn’t have sat there while Arya got killed by Sansa, because Bran would have known that wasn’t the way things had to go. He would have known 'I need to be here to reveal what the truth is.," he said.

Well, we are happy things played out the way they did and it is of great satisfaction to see Littlefinger be the victim of his own games and the ensuing peace that prevailed in Winterfell.