He has no hesitation in insisting that Emile Heskey controlled the ball with his hand just before Michael Owen swivelled on a sixpence to grab a late equaliser on Saturday.
"I think it was handball from Heskey - which meant bad luck for us.
"I am very, very disappointed because we deserved to win against Liverpool."
It is the second time in four games that what appeared a blatant handball has been missed against top class opposition - Patrick Vieira also got away with a similar offence in his own penalty area recently, denying the Hammers what could have been a match winning penalty.
At least, however, the performances are proving to be consistent, and former Liverpool striker John Aldridge, in his role as a radio pundit on Saturday, said no one had given the Reds so much trouble this season.
But Tomas, who has played 14 times for West Ham since his arrival from Fiorentina in September, feels there is no fundamental difference from earlier in the season when results weren't going so well and adds: "I think nothing too much has changed, just that all the team is playing well and confidence is higher."
As for his own game, he adds: "I am very happy here but I can still play better.
"I'm very happy with the fans as well - they were brilliant against Liverpool."
Paolo Di Canio returns from suspension against Leeds, while the two full backs, Nigel Winterburn and ever present Sebastien Schemmel, are just one yellow card away from a one match ban.