The former Tottenham striker was targeted by Hyndman as the major threat for the Galaxy at FC Dallas Stadium but he feels that the Galaxy ace, who helped his side to a 1-0 away win, got away from his team's defence.
"It didn't look like it, but a big emphasis in today's game was to not let Keane get free," Hyndman said.
"It seems like when we had the ball our center backs completely forgot about him he's the last guy in the attacking third you want free.
"He caused us a lot of problems, I don't know if we ever got that right."
The loss forced Dallas down to eighth on the Western Conference table whilst Galaxy, who were without David Beckham and Landon Donovan, remained fifth in the West with their fourth win in five outings.