Allan McGregor does not believe Scotland deserved to lose to Wales and has admitted the refereeing calls were difficult to accept.
Craig Levein's men were on course for a first win of their World Cup qualifying campaign in Cardiff on Friday night when James Morrison fired them into a first-half lead.
Steven Fletcher then had what appeared to be a perfectly good goal disallowed, before the home side hit back to snatch the points through a late Gareth Bale double, which included a debatable penalty.
Scotland's hopes of reaching the Euro 2012 play-offs were shattered following a dubious penalty decision in favour of the Czech Republic, while Macedonia claimed a point at Hampden last month thanks to what appeared to be an offside goal.
And McGregor is unhappy that questionable decisions have cost the Scots once again in Wales.
He told the Scottish Football Association website: "I don't think we deserved that result, I really don't. I have said it already and I will say it again: some of the decisions we have had to contend with are really hard to take and it was the same again on Friday night.
"I am not taking anything away from Wales and I know it sounds like sour grapes but it is true and you only have to look at some of the incidents.
"If you look back to the penalty against the Czech Republic at Hampden - that cost us a place at the play-offs.
"It happened against Macedonia when their goalscorer [Nikolche Noveski] was offside and again on Friday night, when a perfectly good goal was chalked off."
Charlie Adam's cross was deemed to have swerved out of play before reaching Fletcher, despite television footage appearing to show otherwise.
McGregor added: "From where I was, I saw the flag go up early so assumed it was offside. Then the referee gestured that the cross had gone over the byline.
"We couldn't believe it when we saw the incident afterwards and saw that the ball was well in play and that Steven's header was absolutely fine.
"It makes it that much harder to accept because at 2-0 down the game is over - no doubt about it.
"We were playing well and creating chances and the second goal would have killed Wales off.
"Instead, they get a soft penalty and arguably they should have been down to 10 men in the last 10 minutes."