The donation in Scharf was made in 1967 before Congress amended section 170 to disallow a charitable contribution deduction for the contribution of a partial interest in property, and the standardapplied in Scharf was subsequently superseded by the quid pro quo standard for charitable contribution deductions established by the Supreme Court in Am.
McArdle had argued that old case law from the 1800s, with a presumption of owner negligence from a wandering horse or cow, had never been overruled though courts more recently had applied the other standard.