"It is absolutely appalling and I feel sorry for Oxford's fans," said Williams. "The way he administered the Vale took us down and down."
Deakin, aged 48, angered Vale fans by suggesting he had bought a stake in the club worth £100,000 ahead of his election to the board.
In fact, he had been issued with "nil-paid shares", and never paid a penny for them.
Deakin and the former Vale board were also criticised for misleading supporters over the extent of the failed Blue Sky International investment deal, said to be worth £8.5m.
The Firoka Group, owned by former Oxford chairman Firoz Kassam, did not consult Vale's administrators before offering the post to Deakin.
"If they'd have contacted the club or the supporters' club, I don't think the reply back would have been too pleasant," added Williams who led calls for Deakin and his fellow directors to be quit,
Deakin got the Vale job in March of last year, but resigned eight months later after a series of revelations about the running of the club under his stewardship.
He was serving out his notice when he was made redundant by the club's administrators last month.
Despite being mired in controversy during his time at Vale Park, the company who own Oxford's Kassam Stadium, the Firoka Group, have apparently offered Deakin a quick route back into the game.