In that test at Toulouse, Williams was pressing for the line when he was hand-tripped.
"I stumbled and instead of falling, I tried to keep my feet and my left knee pushed the femur out the back of the pelvic girdle," he recalled.
Only insistence from doctor teammate Lawrie Knight, manager Ron Don and the work of a top orthopedic surgeon got Williams sorted otherwise he could have been left with a limp.
In between those remarkable episodes, Williams was involved in the momentous series loss to the Lions in 1971 and the extraordinary waterlogged test against Scotland at Lake Eden Park four years later.
The Lions brought a strong squad with a golden backline, names which Williams delivers with unerring recall. JPR Williams, Barry John, Mike Gibson, Gareth Edwards, Gerald Davies, John Dawes-the names flow as strongly as Williams' admiration for their calibre.
Scotland came without that sort of pedigree in 1975 but their Eden Park test remains one of the more extraordinary in All Black history. Williams was a central figure with two tries as he jet-boated across the surface in the 24-0 victory.
"It had rained for 24 hours before the game. My Dad went to the game to watch, saw the conditions, threw his tickets out the window and went home and watched it on TV," said Williams.
During his rugby career Williams studied law. On the '72-73 tour he studied at night on a mattress in the bath so he would not disturb his roommate and sat exams in London, Swansea and Cambridge before claiming his degree a few years later.
He coached Auckland with his great Ponsonby mate Maurice Trapp for five seasons when they lost just three games and drew another. Williams used that influence to reconnect with Samoa and their startling impact at the 1991 and 1995 World Cups.
It rankled him that those results produced nothing for Samoa when rugby went professional in 1995. Williams remains connected to that side through his sons, has helped coach the Hurricanes and was president of the NZRU during the 2011 World Cup triumph.
Statistics
Date of birth: 3 October 1950
Position: Left wing
Matches: 113
Tests: 38
Test debut: 25 July 1970 v South Africa, Pretoria
Last test: 9 December 1978 v Scotland, Edinburgh
Province: Auckland
Test tries: 10
Test points: 71