As Warriors forward Demetric Vaimauga conceded he had knocked the ball on in a confusing ending to Friday's match at GoMedia Stadium, Webster said his men were the architects of their own downfall in Auckland.
Webster's side came into the first of their final two games of the regular season knowing two wins would keep them locked into fourth spot and they thought they were halfway there when centre Adam Pompey crossed in the 76th minute.
Pompey had scooped up a loose ball after Eels fullback Isaiah Iongi and Vaimauga competed for a kick to the air.
Referee Peter Gough had given the try the all-clear before bunker official Chris Butler overturned the decision, claiming Vaimauga had knocked the ball on.
Bunker officials can only overrule on-field calls if the evidence is conclusive.
There did not appear to be clear evidence on the angles used by broadcasters, although the bunker has access to different cameras.
Vaimauga later admitted in a TV interview he knocked the ball forwards as Webster put his players, not the officials, in the crosshairs.
"I don't know if there's enough evidence to overturn it (and say) that he touched it," Webster said.
"I can't tell if he touched it. I'm pretty biased with four minutes to go, so I'm going to have to rely on everyone else and watch it in slow mo.
"I can promise you right now we should not have been in that situation through the way we played."
The loss has major ramifications for the NRL's top four with Brisbane and Cronulla hot on the Warriors' tail and boasting superior for-and-against records.
The Broncos see out their season facing North Queensland on Saturday before a meeting with Melbourne, while Cronulla host Newcastle on Sunday and then take on Canterbury the following week.
Not that Webster will be losing sleep working out the permutations.
"It doesn't matter, wherever we finish is where we'll finish," said the Warriors coach, whose side travel to face Manly in their final game of the season.
"I'm no mathematician, but if we win and those teams lose, then we're still a chance for top four."
The chaotic ending took the shine off another encouraging night for Jason Ryles' Eels.
Parramatta have made great strides through the back half of 2025 and the scalp of the Warriors will sit alongside wins over Brisbane and the Sydney Roosters in recent times.
"It's small steps forward, to come over here and play against a committed footy team that's playing for a top-four spot was a good night for the club," Ryles said.
Except for late on when Pompey's eventual no-try was awarded and then chalked off, the Eels never relented their lead, with Josh Addo-Carr and Jack Williams putting them ahead 12-4 at halftime.
Pompey scored the Warriors only first-half try before setting up Roger Tuivasa-Sheck in the 55th minute.
Iongi and Warriors forward Leka Halasima both scored second-half doubles before the game's pivotal moment occurred.
Pompey thought he had scored the winner but Gough and Butler quickly killed his joy.
7°C