United boss Sir Alex Ferguson claimed van Persie could have been killed by the Swansea defender after the Dutch striker was struck on the back of the head from close range.
"Robin van Persie is lucky to be alive. It was a disgraceful act from their player," Ferguson said after seeing his side held to a 1-1 draw.
"He [Williams] should be banned by the FA. Robin could have had a broken neck."
Houghton believes those comments were over the top but insists he can understand Ferguson’s anger over the incident.
The former Liverpool and Ireland star told the Alan Brazil Sports Breakfast Show: “For me, it’s unnecessary. Acts like that are cowardly.
“It’s a bit like spitting in someone’s face. That’s not showing strength of character or showing you’re a hardman. It’s a cowardly act.”