It is not the kind of reception that any politician would have wanted to a keynote address: a metaphorical but unmistakable two-fingered salute.
Last week saw Welsh headteachers finally snap, after a year in which they have been repeatedly attacked for underperformance, despite massive funding issues.
In recent months, educationalists in the principality have become used to hearing how bad things are, with education minister Leighton Andrews - who is behind a wide-ranging programme of reform - regularly accusing schools of complacency.
But, last week, Welsh school leaders sent a massive vote of no confidence to their political masters in the Assembly Government when 92 per cent of delegates at heads' union ASCL Cymru's annual conference said they thought the education system was "constrained". Only 2 per cent said they thought it was "confident".
The day before, Mr Andrews had reiterated the importance of school leaders to the success of his 20-point action plan, drawn up in the wake of Wales's disastrous Pisa (Programme for International Student Assessment) results.
But his assertion that heads would be "instrumental" in moving the system from "fair to good" was given short shrift.
ASCL general secretary Brian Lightman, formerly a headteacher in Wales, attacked Mr Andrews' comments.
"I think we have a good system in Wales, aiming to be excellent. We share his aspirations, but we believe there's a vast amount of innovative practice," Mr Lightman said. "Behaviour in most schools is good, standards have risen and attainment is higher than it has ever been. We have great strengths we need to build on."
ASCL Cymru president Tim Pratt, headteacher of Caerleon Comprehensive School in Newport, said it was too easy to point the finger of blame. "School leaders are not the problem; together with our colleagues, we represent the solution," he said. "School improvement is not a quick journey. It takes time and persistence, and our agenda is more than full.
"It's not so much the goalposts have moved; we're playing on a different pitch. The reality is we have to roll up our sleeves and get on with it as we always have done. I have never come across a head who doesn't care deeply about their school or the success of their pupils."
Indeed, he went further. "We can achieve what you want," Mr Pratt said, addressing Mr Andrews directly, "but you need to trust us to rise to the challenges and work with us to ensure that every young person in Wales succeeds."
ASCL Cymru secretary Gareth Jones said school leaders did not disagree with most of what the minister was trying to achieve, but said he must trust them on how to get there and give them meaningful support."
Another vote revealed that heads are especially vexed about banding and, in particular, the impact the publication of banding positions will have on their schools and communities.
Mr Jones said these "unintended consequences" could be hugely damaging not only to heads' own institutions but also to their relationship with ministers.
And in yet another poll - a finding that should worry politicians - some 88 per cent said they were "doubtful" or "very doubtful" that their local authorities had the ability to help them to improve standards.