Both managers had reason to curse Sunday's referee after the Hornets beat Boro 1-0 on Sunday, thanks to a Jose Holebas stunner in the second half
Middlesbrough head coach Aitor Karanka pointed the finger at referee Roger East after Sunday's 1-0 defeat to Watford, despite Boro right-back Antonio Barragan somehow avoiding a red card.
Jose Holebas' stunner sealed all three points for the Hornets at the Riverside, though Nigeria striker Isaac Success was man-of-the-match for an all-action display, which Barragan totally failed to handle.
The summer signing from Valencia ought to have been dismissed just past the half-hour for a foul on Success, having earned an earlier booking for a similar offence against the same player.
East drew the ire of both sets of fans during the game, with Boro having three penalty appeals turned down, but Karanka was frustrated by the official's perceived acceptance of time-wasting tactics from Watford as Boro were chasing the game late on.
"We conceded a goal in the second half and after that it was impossible to play," said the Boro boss. "They showed that they are much more experienced than us and in the second half it was impossible to play.
"The ball has been more time stopped than in play. I don't know how many times they went to the floor, I don't know how many minutes it took for every single throw in – it was really difficult for us to play, we didn't know to play in that way.
"I don't want to blame anybody, I want to say that we couldn't play in the second half the way we like to play.
"That is my concern, why they can waste time, why they can do whatever they want and every single player for us is a yellow card. This is my concern, not the yellow cards."
Watford boss Walter Mazzarri disagreed with Karanka's assertion and said Miguel Britos was genuinely injured, before hailing his side's defensive effort to leave Teesside with a clean sheet.
"I don't think [we were time-wasting]," the Italian said. "Britos was injured and if someone is injured he waits on the floor and waits for the medic to come. I don't know what Aitor Karanka refers to, but I don't think we were time-wasting.
"We were missing many of our starting defenders, but when we have our full team in a full condition, I can say it'll be very difficult for other teams to score against us. Today, it was more about our merit that Boro didn't score."
Mazzarri wryly kept his counsel when asked about Barragan's performance: "We all know the rules, it was very evident that Barragan fouled, but everyone who knows me knows I don't tend to talk about the referee and I won't today.
"We've played better in other games, for sure, compared to today. It was enough, but we can do better. I'm happy with our defensive performance but I want my team to create more opportunities and be more attacking."