Many inside Villa Park thought the hosts had claimed victory when Morgan Rogers swept home with virtually the last kick of the match.
But celebrations were short-lived as Spanish referee Gil Manzano ruled the goal out, deeming Diego Carlos to have fouled visiting goalkeeper Michele Di Gregorio, causing the latter to spill a free-kick into Rogers’ path.
Several Villa players, including Rogers, celebrated thinking Manzano had awarded a goal and more than two minutes passed before it became clear precisely what the official had decided.
Yet Cash claims he knew from the start, explaining: “He (the ref) was stood pretty near me so I could see he had blown (for a foul).
“I didn’t even run over and celebrate because I knew. It went so loud I don’t think anyone knew it wasn’t a goal. Maybe we were unlucky but overall it was a decent performance and one to build on.”
Villa boss Unai Emery later described the decision to disallow the goal as “very soft” and claimed it would likely have stood in the Premier League. Cash, who made his Champions League debut on Wednesday, said players had now accepted the fact more fouls would be awarded in European competition.
Both Youri Tielemans and Leon Bailey were booked in the opening 10 minutes of the game for what appeared relatively minor infringements.
Cash said: “Obviously, European football is a little bit different. No disrespect to the referees but you probably have a lot more fouls in European football, as we found out last year in the Conference League.
“You have to adapt. You can’t really touch a lot of players now, or it is a foul.
“I said to the referee tonight, it is difficult, in big games managing every situation. We all make mistakes and sometimes the refs are going to make mistakes.
“That is just football, you know. We are all humans. We all make mistakes and he has a big job tonight refereeing the big game. It is difficult. They try to do as well as they can and we do as well. Overall it is fair.”
Cash saw Wednesday night’s result as a positive for Villa despite it extending their run of winless matches to seven, ahead of Sunday’s Premier League trip to Chelsea.
Villa looked the more likely team to break the deadlock against a heavily depleted Juventus team, though it required a brilliant save from Emi Martinez to deny Francisco Conceicao midway through the second half.
“To be honest I did think that was in but yeah, it was unbelievable,” said Cash. “That is what he (Martinez) is there for, he’s a goalie.
“He does it every week, so it is not new for him to pull one out of the bag.”
Martinez and Villa have now kept four clean sheets in five Champions League matches and are yet to concede at home in the competition. By contrast, they have recorded only one shut out in the Premier League.
“With recent results we have not been strong enough defensively,” said Cash. “I think all over, all of us will say we have not been at our best and Wednesday was a building block, a clean sheet and a better performance. Hopefully we can take that on.
“I don’t think it was a performance where you look at it and think, they haven’t won in seven.
“I think we fought all over the pitch and dominated in a lot of spells. Obviously we are not happy about not winning in seven but the clean sheet and the performance was decent.
“Chelsea are doing well at the minute, got a new manager in the summer so we know it is going to be a tough test but it is one we are looking forward to. We need to go there, get a result, get a win and kickstart our Premier League form again.”