The Supreme Court has resolved this ambiguity. The true doubt rule does not alleviate the claimant's burden of going forward. Before a claimant can benefit from the rule, he must put in some evidence showing the presence of pneumoconiosis. That Freeman was able to counter this evidence with equally probative evidence is of no consequence to Jones's burden of going forward. Jones satisfied his burden by producing prima facie evidence of pneumoconiosis.
Freeman is wrong.
The burden of persuasion may be legislatively or judicially assigned to a specific party to establish a particular fact. When it is applied, the true doubt rule allows an ALJ to invoke the presumption of disability in favor of a claimant once the claimant has produced prima facie evidence of pneu- moconiosis that has not been overcome by the employer's opposing evidence. The employer then must persuade the ALJ that the claimant did not have pneumoconiosis. The question before the Court in Mullins Coal was whether one item of evi- dence qualifying a claimant for the presumption is always sufficient to invoke it. The Court answered in the neg- ative, interpreting 20 C.F.R. sec.