Medical researcher: At the Flegco Corporation, all employees whose work involves lifting heavy objects wear back belts to prevent back injuries.
Conclusion
Back belts do not help to prevent back injuries.
Evidence
Everybody at Flegco that does heavy lifting wears back belts, and a study found that employees who wear back belts are more likely to suffer back injuries than those who don't.
Evaluate
With an Anti-Causal conclusion like this, we're trying to object by arguing that there is a causal benefit to wearing back belts.
Given That the people who wear back belts are more likely to suffer back injuries than those who don't How Could We Argue That back belts do help prevent back injuries.
Our normal objections for Anti-Causal arguments are: - the two groups aren't fair to compare to begin with - things would be even worse without X (in this case, back belts)
In this argument, we already know one salient difference between people who do / don't wear back belts: the people who do wear back belts have work that involves lifting heavy objects. The people who don't wear back belts don't have to lift heavy objects.
I'm not surprised to hear that "people, wearing back belts, moving furniture all day" have more back injuries than .
This would be like arguing,
Of course they do -- it's just that people who wear bulletproof vests have jobs that put them in the line of fire, so their chances of dying from a gunshot wound are much, much higher to begin with than are people with other jobs.
Goal
Find an answer saying that the author is failing to consider that things would be way worse without back belts for all these people doing heavy lifting, or pointing out the objection that it's unfair to compare the likelihood of back injuries of belt-wearers vs. non-belt-wearers, since the former have such a higher chance of getting back injuries in the first place based on the nature of the heavy lifting work they do.