In the moments that followed Liverpool's 1-1 draw with Chelsea on Saturday evening, Jurgen Klopp made it very clear that he was not happy with referee Michael Oliver for not allowing a substitution minutes before Willian bagged the equaliser.
Klopp had wanted to bring midfielder Adam Lallana on with instructions for the defensive unit where Ragnar Klavan would have been moved to a position that could have prevented the goal, according to the German, but the referee said no, and play continued for four minutes before the next break in play.
Oddly, Michael Oliver claimed he refused the substitution because he felt Klopp was trying to waste time, something that isn't really any of his business, and footage of the Liverpool manager's reaction to the goal as it went in shows just how unhappy he was.
Liverpool's 'Tunnel Cam' picked up Klopp berating the fourth official with such high volume that he could be heard from the tunnel, and over the noise of almost 55,000 football fans.
That was... Loud.
To be fair, a referee really shouldn't refuse a substitution because he believes it is to waste time, as he is not in a position to judge that, and surely adding time on would be a better solution?
It is, of course, highly possible that Lallana coming on to the pitch would have done nothing to stop the goal, but we really should have been left to find out for ourselves.
You can check out the rest of the Liverpool vs Chelsea 'Tunnel Cam' below, featuring a lot of love for Mo Salah from his former teammates.