An arbiter 100% cannot stop a game because of that. Time management is part of the game in speed chess anyway, and for longer time controls there is usually a delay/increment so running out the clock in a clearly lost position isn't viable.
I slightly misremembered; the player stops the clock and calls the arbiter; if the arbiter agrees that their opponent is not attempting to win by normal means, the arbiter may award a draw. There is a 2 minute bonus to the opponent if the arbiter disagrees with the player making this claim.
