Millwall striker Neil Harris feared for the safety of his team-mates at Upton Park but believes there would have been greater outrage if it was visiting fans invading the pitch.
West Ham supporters poured over the advertising hoardings after their goals in the Carling Cup win, with Kenny Jackett's players heading off the field at one stage.
"It was extremely hostile and volatile,'' Harris said. "All my concern was for my team-mates. At one stage it wasn't very pleasant.
"We've had it at Millwall when fans come on to celebrate and everyone makes a big hoo-ha about it. I'm sure if it was our fans on the pitch people would be very keen to report that.
"Anything can happen when they are on the pitch but most of the time fans are on the pitch to celebrate a goal, not to attack players.''
Harris relishes playing in local derbies and was disappointed that the evening descended into chaos.
"I've played in these games before and know what it is all about, big local derbies and red-hot atmospheres,'' he said.
"They are terrific games to play in and that is why you play football. It means so much to the supporters of both clubs but sometimes they get a little bit over-zealous.
"As a senior player you do not lose concentration because it is what happens between the white lines. For young players it is extremely difficult but you play football for these type of matches and it is a learning curve.
"This was no different, a terrific atmosphere and a learning experience for the young lads. They will take something out of that.''
After taking West Ham to extra-time, Harris added: "We were very close to winning our big local derby and giving bragging rights to our fans.
"I still think our fans will class it as bragging rights coming to Upton Park and being in front for so long and playing so well.
"At the end of 90 minutes it was 1-1 and there was a disputable penalty in extra-time.''