Only watched a little of the video, until I saw one of the requests returned an access token with lots of repeated data. Was very surprised when I base64 decode

Only watched a little of the video, until I saw one of the requests returned an access token with lots of repeated data. Was very surprised when I base64 decoded that and found it was just "\uDFFF\uDBFF" repeating over and over. Maybe that was data coming from his exploit, seems a bit weird for that to be in an access token anyway. I had the sound muted, so maybe he mentioned that.