Diogo Jota struck in the second-half for Liverpool's 1-0 win, though Everton insist Luis Diaz was interfering in play from an offside position in the lead up.
“In the moment, obviously, I can't see what's happening,” said Pickford afterwards. “But Jarrad (Branthwaite) said it was a stone-wall offside straight away.”
“It's a big debate and we'll see what the referees come out and say but I think it went to VAR. As a team I think we thought it was offside. We’re disappointed with the decision, but they can't always be perfect.”
On Everton defender James Tarkowski's challenge on Alexis Mac Allister in the first-half, Pickford continued: “It's probably a bit high force in this day and age, but he's done what he's done.
"He's apologised after the game and the VAR say it’s not a red card, so that's the decision."
The defeat ended Everton's nine match unbeaten run.
“I think it's disappointing not to get a result because it would have been nothing better than getting a result for the fans and for ourselves to keep that momentum going, but we take confidence, and we go again on Saturday,” said Pickford.
“It's a derby game, it's a big game for us and I think because we're on a good run. We go in with confidence and even getting beat, we'll still come out with confidence from it because the fight, the determination to be resilient was quality from the lads – some of our defending and some of our blocks.
“It's about creating that next level with a bit of quality when we get the ball and taking the sting out of the game sometimes with a few passes.”
He added: “We never stopped fighting; we kept in the game. A few chances for them, a few chances for us and they get their chance.
“We didn't give up, we kept trying to push, push. They’re the league leaders and they’ve been good all season and to still be in the game all the way through was good.
“But it was a lot of fight from the lads and credit to everybody because we put a shift in but we're also very disappointed not getting a result.”