The Post said the boy had been "perpetually teased for his nonconformity and presumed homosexuality." Romney said Thursday he does not recall the episode, but apologized for his behavior and denied any suggestion that he had targeted students because they were gay.
McDonald told The Inquirer in an interview on Thursday that the incident, as described by classmates he had known well, was consistent with the Romney he knew as a teenager.
"I wasn't surprised that Mitt might have done that," said McDonald, who graduated with Romney in 1965, became a lawyer, and went on to serve as a top attorney in the investigation into the city's 1985 bombing of the MOVE compound.
"He liked to make people laugh," said McDonald, who lives in Haverford Township and has a law practice in Center City. "He often pushed the envelope - not necessarily in a bad way, but like he was trying to see how far he could get and still be cool."
McDonald added that he does not condone the attack as described by the Post.
"Mitt was a friend of mine back then, and I don't agree at all with him politically," said McDonald, a backer of President Obama. "He used to do stuff all the time that, frankly, was on the edge."
McDonald said he received a call from Romney's brother in light of the Post's account, asking that McDonald share recollections with the Republican presidential contender's campaign office. He said he would.
McDonald said he did help hatch one prank - in which Romney had impersonated a police officer. (Romney, he said, even placed a flashing orb atop a car for verisimilitude.)
The lawyer recalled: "A friend of mine and I were out parked with our dates and Mitt was going to come up behind us in a police car and, I think, the military uniform of a friend of ours. But he was simulating a police officer."
As planned, Romney pulled their car over, demanded the vehicle registration, and asked for the keys to the trunk - where he "found" the bottle of bourbon McDonald had taken from his dad and planted as part of the ruse.
"He told me and my friend to get out with him, and that he was taking us in," McDonald remembered. The idea was to spook the girls.
McDonald speculated as to why Romney relished concocting such elaborate schemes. There was an impression, McDonald recalled, "that he sort of was trying to figure out how to fit in."
Why, McDonald was asked, would the son of the Michigan governor have felt out of place at an exclusive prep school?
"Who knows?" McDonald said. "People are strange."
Contact Maria Panaritis at 215-854-2431 or firstname.lastname@example.org or @panaritism on Twitter.