Out at first ?

[wargy]

This occurred recently at a men's slowpitch game. Batter hits a grounder towards third, whom fields the ball and throws to first. The runner arrives about the same time as the ball. The throw was in the dirt and first baseman never makes the catch but the ball drops to his feet so there wasn't an overthrow. The runner steps on the base and continues a few strides, definitely, outside the baseline. He stops after the third or forth step and turns to see where the ball went, since he new the ball was in the ground. No move was taken towards second, since the first thing he sees is the first baseman picking up the ball. The umpire waited for the first baseman to pick up the ball and watched to see if he would tag the runner or first base.

My question for this situation is. Is the act of stopping after a few strides and looking for where the ball went enough to be construed as an attempt towards advancing to second? The umpire made it seem as it would.