PORTLAND, Ore. -- Ever since Dr. Gary Lee was fatally struck by a watermelon-size rock and plunged down the north side of Mount Hood, his son, Devin, has worn his father's baseball cap, which the doctor had chosen over a helmet.

Dr. Gary Lee

Devin Lee saw the 55-year-old cancer specialist disappear into a deep gully and found his hat as he searched for him. A rescue team found the doctor, killed by blunt force trauma to the head.

More: Doctor's body recovered

Two days after the Sunday accident, a Portland Mountain Rescue veteran questioned the decision to forgo helmets.

All climbers on any Mount Hood route should wear helmets, said Steve Rollins, one of the rescue team members. "There is too much loose rock," he said.

Rollins also questioned the descent via the Cooper Spur route, a more exposed and dangerous route, especially when snow starts to melt. A safer choice, he said, might have been the easier south side routes.

Their effort was at the outer edge of the envelope for safe rescues and recoveries, he said.

But Lee's wife, Dr. Stephanie Harris, said he had climbed Mount Hood more than 40 times and knew it from all sides.

Considering the size and speed of the boulder, family members said they weren't sure a helmet would have helped.

"That same question was in my head," Harris said. "On that particular day, he made that choice and felt that it wasn't necessary. ... The reality in this particular instance? Chances are it wouldn't have made any difference."

Devin Lee began climbing with his father at age 16.

As the two descended, they found the mountain more exposed than they expected, but when they reached the snowfield they felt safe enough to unrope and put on their crampons, Devin said.

He saw the boulder hit.

"I shouted after him," he said, watching as his father "was ragdolling down" the snowfield. Devin then descended after him, shouting out to anyone who might hear.

"All I could hear was my echo," he said.