Chelsea manager Rafael Benitez believes the officials cost his side a much-needed win after Luis Suarez scored in the seventh minute of stoppage time to seal a 2-2 draw for Liverpool at Anfield on Sunday.
Oscar opened the scoring for the Blues before Daniel Sturridge equalised against his former side early in the second half.
Chelsea restored their lead shortly after with Eden Hazard converting from the penalty spot, but Suarez scored with the clock showing 96 minutes and 34 seconds to leave Benitez fuming.
"I was disappointed with the late goal conceded," Benitez said. "Especially because I can't understand why there were six minutes and 45 seconds [stoppage time] - a very strange decision.
"Some games you have six substitutions and they say three or four minutes. In this case six minutes, a throw-in for us and the game was over, and still 45 seconds more. It is difficult to explain.
"We have to analyse why we didn't stop the cross and why Liverpool scored, but still in the normal circumstances we would have finished the game having won against a good team.
"They were pushing but we were defending well and had our chances in counter-attack in terms of dangerous situations.
"Sometimes when they try to explain added time they put substitutions as 30 seconds, sometimes they say 40 seconds, sometimes one minute - but every single game you have three or four minutes added, five minutes if it is a lengthy incident - but six minutes 45 seconds?"
Benitez's return to Anfield was overshadowed by Suarez's apparent bite on Chelsea defender Branislav Ivanovic, although the Blues boss believes the excessive amount of stoppage time should steal the headlines.
"I didn't see the incident so I am disappointed with the late goal," Benitez said. "A lot of people are telling me this and that but I didn't see. For me the headline would be why six minutes and 45 seconds, that is the only one I have to understand."