Welsh referee Nigel Owens says he will be "more aware" in future if there is any repeat of the infamous 'Bloodgate' scandal.
Owens was in charge of last season's Heineken Cup quarter-final between Harlequins and Leinster at the Twickenham Stoop, when Quins wing Tom Williams bit on a blood capsule and faked injury.
It created monumental fall-out following Quins' desperate and illegal attempt to get injured star kicker Nick Evans back on the pitch to try and win a game they ultimately lost 6-5.
Dean Richards, the director of rugby at Harlequins at the time, received a three-year worldwide coaching ban for his role in the affair and orchestration of an attempted cover-up while the club's then physio Steph Brennan was suspended for two years.
Williams, meanwhile, landed a one-year ban which was reduced to four months on appeal.
Quins were also hit with a six-figure fine, although they avoided expulsion from this season's Heineken Cup, which they begin away to Cardiff Blues on Saturday.
Owens, one of the world's leading referees, said: "Maybe looking back now I am a bit disappointed that I didn't (do more), but you didn't expect this sort of thing to happen, even though I had my suspicions as he (Evans) had been warming up.
"If the same thing happens again, I will certainly be more aware what we as officials need to do now.
"If there is any doubt, then we will have a look at the wound. At the time, though, I didn't and that is probably my one regret.
"I could see there was blood in Williams' mouth. It wasn't pouring out like you saw when he came off the field. I asked the physio if it was blood and he said 'yes it is, he has got a cut'.
"If I had seen what the footage showed, of Williams spitting blood out and winking, that would have aroused my suspicions even more and I would have done something then.
"I probably would have asked to have a look at it and asked Williams to wash his mouth out with water so I could see where the cut was. I would have stopped him and asked for further medical advice.
"But if the medical guy had said to me the cut was behind his teeth, then I would have taken his word because I am not medically trained."
Owens though insists the whole unsavoury episode has not put him off the sport.
"It hasn't put me off the game because it has been dealt with," he told the Daily Telegraph.
"Looking back now, everyone involved in the game is probably pleased that the dropped-goal attempt by Evans didn't go over, because if it had done it would have been a total mess.
"People who were behind it were found guilty of it, and they had to take the consequences.
"If it was orchestrated by Dean Richards, as has been reported, then he has got to take the consequences. If you live by the sword, you have to die by the sword."