Cameron Ciraldo has questioned Jacob Preston's sin-binning and labelled his battling Canterbury "easy targets" after the Dolphins swept them aside in Brisbane.
Trailing by eight, the Dolphins scored 40 unanswered points on Thursday night to prevail 44-12 and consign the Bulldogs to a sixth defeat in their last seven starts.
A 6-2 penalty count in favour of the Bulldogs flipped to finish 8-8, and the Redcliffe side capitalised, running in eight tries to edge into the NRL's top 10.
Dolphins winger Jamayne Isaako scored two of his three tries while Preston was in the sin-bin, marched after collecting halfback Isaiya Katoa after he had offloaded the ball.
From that point on, the Bulldogs were starved of possession.
"It just killed us," Ciraldo said.
"A lot of it was self-inflicted, but there will be some questions I'll ask of it as well.
"I'm not watching the game thinking, 'We are so ill-disciplined here'.
"But we continually get hammered by penalties ... especially inside 20, with massive momentum-swinging penalties.
"There's ones we are totally in control of, but I feel like we're an easy target at the moment.
"I don't understand the sin-binning, but we have to be tougher through that period."
Semi-finalists last year, the Bulldogs were 3-1 after three-straight wins but have fallen away since then.
Their only win since mid-March has come against Penrith.
"Disappointed with a lot of parts of it ... I saw improvement, but a lot of parts where it was really poor," Ciraldo summed up.
"All the games have been a little bit different, but discipline is hurting us."
He said indecision on the edges in defence had been exploited by opponents and left his forwards frustrated.
"Soft decisions ... our forwards are working their arses off, then they have that disappointment of sitting behind the tryline," he said.
The Bulldogs return to Suncorp Stadium next week for Magic Round, set to face Cronulla on Friday.
