Mo Salah scored a hat-trick as Liverpool thrashed the Cherries to move top of the Premier League temporarily.
The other goal came on 68 minutes when Steve Cook scored past his own goalkeeper to make it 3-0 at the time, and it was Robertson's cross which led to the own goal.
The Scotland left-back is enjoying a friendly competition with right-back Alexander-Arnold to see which player bags the most assists come the end of the season.
And Robertson says that the Liverpool defender wasn't pleased when he tried to claim Cook's error as a goal of his making.
“I tried! [to claim it]. I don’t think the lads are giving me it. I’ll try to argue it,” he told the Reds' official website.
“I think an assist is the second-last person to touch the ball – that was me, so I’ll be trying to claim it. But as soon as I walked off, Trent wasn’t too happy. If it counts, it counts; if it doesn’t, so be it.”
Robertson, an £8 million signing from Hull in 2018, has set up five goals for Liverpool in all competitions this season, while the England international only has the two under his belt so far.
The Scot will move four ahead of his fellow full-back if he is accredited with forcing the Cook own goal.
Friendly rivalries aside, Jurgen Klopp's side remain unbeaten in 16 Premier League games now.