It was the manner of the defeat that hurt Bullen and his post-match interviews were eerily similar to when the Owls were humbled by Burton Albion at Hillsborough on New Year's Day in 2018.
Bullen was left seething with the players "unacceptable" and "lethargic" performance last weekend. He pulled no punches, criticising the team's "schoolboy errors" and accusing them complacency.
"If our players want to be successful, they have to be mentally stronger than they were (against QPR) because it looked as if we had got 1-0 up at half-time and they thought they had done the job and would cruise through it," said the caretaker manager.
To his credit, Bullen held his hands up and acknowledged it was an error in judgement in changing their formation from 4-3-3 to 4-4-2. It did not work and Wednesday were overrun in midfield.Bullen made some tactical errors, but the players need to take a good look at themselves in the mirror and ask ‘did I really do enough?’
The Owls have one of the oldest squads in the Championship, but where were the leaders in the group when things started to go wrong in the second half? Too many senior pros went missing.
Bullen said: "We have proven in the past that we have got the mentality to do it (in this league) but, once or twice this season, I think for whatever reason, nobody has really taken the game by the scruff of the neck and become that driving force in there.
"At times against QPR, it felt like we were a group of individuals rather than a team. We need to be better than that and the players also know that."
There is no disputing the fact that Wednesday have some very talented individuals in their ranks. The likes of Keiren Westwood, Tom Lees, Barry Bannan, Sam Hutchinson, Adam Reach and Steven Fletcher would walk into a lot of Championship teams.
But the issue over the last two seasons has been a lack of consistency in performance. You are never quite sure which Owls team will turn up from one match to the next. There are too many average days.
Are some players still living off past glories? Do some think they are better than what they actually are? You could argue that the last time Wednesday were a strong collective unit was in 2017 when they reached the play-off semi-finals under Carlos Carvalhal. Since then two mid-table finishes have followed.
And six matches into this season and Wednesday already trail early front-runners Swansea City by seven points.
There is a culture of mediocrity that has set in at S6 and it is easy to blame the manager for the team underperforming. It is high time the players buck up their ideas and start taking more responsibility...whoever the next manager may be.