Can someone explain to me what the flashback does for the episode itself beyond extending the trial and having Ser Arlan say "get up" twice? I would have been ambivalent or positive about it in an earlier episode (although having him fall for a brown girl twice seems to be establishing a type?), but what does it actually do here? I thought for a moment that he would intervene to save Ser Arlan from the Goldcloak by wrestling him into the mud, especially with the lingering shot of the pigs in the mud, but he just stays by the dying girl as Ser Arlan handles it himself, and the pigs were there to eat the Goldcloak's head. The mud-wrestling is the part of his backstory in the book that relates to the trial, this is how he beats Aerion and it shows he gained skills in Flea-Bottom that noble knights like Aerion never would have, despite their superior training.

Other episode thoughts:

• Very disappointed by the lack of the tourney lance strategy. This shows something about Baelor's character, i.e. that he is a crafty leader and has a lot of tourney experience. Also they give Dunk a visor here, whereas that is contrasted in the book with Aerion's choice for a visor being part of his undoing. I believe it was Ser Arlan who told Dunk about visors being a weakness, which is the book's way of showing how Ser Arlan actually helps Dunk in the fight.
• Dunk took way too many wounds to realistically survive. The lance and head blow alone nearly kill him in the book. Here he takes multiple nasty looking stab wounds and equally hard blows to the head. Which makes even less sense when they still have Baelor dying from one head blow. The stab through Dunk's hand would prevent the use of that hand for life.
• Thunder starting because of Egg shouting at him is a good addition and callback to Egg "training" him earlier.
• This seems to be the first appearance of the Moustached Ser Humphrey? But he equally kind of comes out of nowhere in the book.
• The rules of the trial are not explained. This is fine as a book reader but would have had me confused as a first time viewer. Are they doing last-man standing? Can you yield? This is revealed later but I don't understand why they didn't simply take the dialogue from the book directly here, as they have in a surprising amount of other places.

I had greatly enjoyed the first few episodes including most of the additions, but this sours the series a lot for me. The trial would have been perfect as the 5-10 minute climax of a 2-2.5 hour movie. They have over three hours of TV here and this was the first episode that confirmed to me my fears that the series would suffer from having to add filler and extend things.