you did 26.8k damage to champs he did 24.6k damage to champs
which means the damage had less than a 10% difference despite the fact that you had 9 more kills than him
which stands to reason that he had more efficient damage output as a result of scaling, and would have benefited more from the kills than you, particularly when you already had a void staff and he did not yet have a last whisper.
you also didn't upgrade your trinket but your team maintained vision control because that TF was an absolute warding boss. Also Lee had sightstone, though that's somewhat expected.
now that is a PJSalt thread
same
Is there a link to the match history or something?