This is from David Hogg's V-blog #5. Skip forward to 2:55. He brags about telling some strangers that he met his friend after some situation where he had shot him in the leg. He seemed to really enjoy tricking people on video and highlighted it with "Yes, I said that". https://hooktube.com/watch?v=B36d4AC8nfE
Some people tend to enjoy randomly lying - gives them a sense of control they may be lacking in their lives. Source: I used to do it.
I wonder if his parents changed their last name at some point? He seems to have some ancient skills of deception.
There is video of him being prompted several times to give his programmed lines about the florida shooting.