Cann initially ruled out Roque Santa Cruz's 84th-minute header for offside but after consultation with referee Howard Webb he awarded the goal which ended City's perfect start to the league season at Eastlands.
Hughes said: "He has been honest to admit he had got decision wrong. He flagged initially for David Dunn, but he changed his mind and we're absolutely delighted he was able to do that.
"In the past I've questioned officials but on this occasion he was strong enough to change his mind."
Hughes felt Rovers were good value for a point in the end and told Sky Sports: "We never laid a glove on City in the first half and in the second half we needed a response and I thought we were excellent, we took the game towards them. Another 10 to 15 minutes and we could have won that game.
"It's a positive result, we've got two games coming up (away to Derby and at home to Sunderland) which we feel will help us get points on the board and hopefully this result has kickstarted us."
Darius Vassell put the hosts in front in the 27th minute but within seconds Santa Cruz had equalised for Rovers.
Two minutes later City were back in front thanks to a Ryan Nelsen own goal but Santa Cruz's late header ensured a share of the points.
Midfielder David Dunn added: "In the first half we were a couple of yards behind them, the passing was poor but the lads showed good character in coming back."