Spencer revealed that Galaxy fans were hurling abuse at Dynamo forward Brian Ching, who recently fell out of favour with the USA national team, by yelling 'US reject! US reject' at him.
Spencer defended his own actions by backing up his player he explained: "When you have a guy who has been as decorated as this player has been, scored so many goals for his country and been a great ambassador for the national team, to see the abuse he was receiving it really gutted me.
"American mentality is of giving a chance to succeed," he added. "I thought it was disgraceful. Should I have done what I did? No. Do I regret that I did it? No."
Dynamo head coach Dominic Kinnear also chimed in, saying Spencer is a man who really cares about the players at the club.
"He cares," Kinnear said of Spencer. "And he's sticking up for an important member of our squad going through a tough time. For fans to do that, I think it crossed the line."