The Mexican converted his chance clearly using an arm but with no VAR the officials let the goal stand.
And Ex-England international Matthew Upson believes the former Manchester United man knew exactly what he was doing.
He said: “It’s an intentional handball. Hernandez knew what he was doing.
“But Sergio Rico should have done better for the goal. The punch was so poor.
“You just can’t make those mistakes at this level.”
On Sky Sports commentary Jamie Carragher also gave his verdict and had more sympathy for Hernandez.
He explained: “The thing about a situation like that – be it handball or diving – is that I have a real problem when teams complain about the opposition doing it, the reason being is that your team will do it next week.
“Every team, at certain times, will bend the rules, will cheat, to maximise a situation. It is part of football.
“Is it a good part of football? Probably not, but VAR will clear that up.”
Fulham took an early lead when Ryan Babel tapped home from close range.
But Hernandez equalised before Issa Diop put the Hammers ahead in the 40th minute.
West Ham will look to extend their lead in the second half and move up to ninth in the Premier League.
Hernandez’s handballed effort was his 50th Premier League goal.
He becomes the fifth North American player to reach that landmark after Dwight Yorke, Clint Dempsey, Jason Euell and Paulo Wanchope.
West Ham’s next game is against Manchester City at the Etihad on Wednesday.