Sunderland beat Southampton 2-1 last weekend, boosting their survival chances.
Pantilimon came charging out of his goal, just after Sunderland had taken the lead, and failed to claim the long-ball, allowing Sadio Mane to tap into an empty net.
It was a rare error for the Romanian, who has been one of Sunderland's most consistent performers this season.
“I was not happy with the first goal, to be fair,” Advocaat said. “Against Stoke he [Pantilimon] was brilliant. But I think he hesitated for the first goal [against Southampton].
“If you had a body like him, I would run away if he came near me! But in the second half he saved us at the end, so good for him and good for the team.”
Pantilimon made a brilliant last minute save from Toby Alderweireld which ended up proving vital for Sunderland, helping them to claim a 2-1 victory.
It was a save which went some way to making up for his initial error as it provided a huge win for the side, as they try and climb out of the Premier League's relegation zone.
At the moment the Black Cats are just one point away from safety, so they will need further wins before the end of the season if they are to stay up.
Their first chance to build on the momentum gained from beating Southampton comes this weekend, when Advocaat takes his side to face Everton.