"I felt that there were very some very strange refereeing decisions tonight which really cost us," Mackay told the press after the match. "If he's going to give the penalty to them for handball then he has to do the same for the incident in their penalty area in the first half from Ben Turner's header.
"We also scored a very good goal in the first half that was given offside. Everybody in the stadium that's seen the television footage after the game could see it was a perfectly good goal.
"We need to look at why we're not winning more games at the moment, but there were outside influences on tonight's result."
Next up for Cardiff is a home match against Barnsley on Saturday afternoon.