A claim can contain a true number and still leave you with a false impression.
That is why I try not to begin with “Do I agree?” I begin with “What exactly is being claimed?”
First, separate the fact from the frame.
What happened? Which institution or government actually had the power to act? What time period are we talking about? Is the number absolute, per person, a percentage, a projection or a comparison against an unusual baseline?
Then ask what has been left outside the frame.
A cost can be real while the avoided cost is omitted. A percentage can be correct while the denominator does all the rhetorical work. A national decision can be presented as “Brussels”. A European rule can be blamed for something it explicitly leaves to national implementation.
Next, look at incentives and consequences.
Who benefits from this framing? That does not prove the claim false, but it can tell you where to examine it more closely. What would follow if the audience accepted the claim as presented? Which trade-offs disappear from view?
Finally, keep three labels separate: known, inferred, and argued.
Known is what the evidence establishes. Inferred is a reasonable interpretation that still depends on assumptions. Argued is the conclusion someone wants you to adopt.
Public debate becomes much clearer when those categories stop borrowing each other's clothes.
This method is not a promise of neutrality about everything. Sometimes the evidence is lopsided. Sometimes responsibility is clear. Sometimes a claim is simply wrong.
But even then, precision matters.
A strong European argument should survive contact with the details. If it needs the audience not to ask who decided what, when, under which rule, and compared with what, it probably needs better foundations.