Over-running First Base
The batter-runner is permitted to overrun or overslide first base without the liability of being put out, provided the batter-runner returns immediately to the base.
It makes no difference if the batter-runner overruns first base on the left side of the foul line, as in this case. … This runner, as long as he returns immediately to first, cannot be tagged out.
When is a batter-runner, after overrunning first base, in jeopardy of being tagged out? (Part 2)
However, if the umpire judges that the batter-runner, after touching first base, fails to return at once, he or she could be put out if tagged before returning to first base or reaching second base.
Remember, this rule applies to all batter-runners, including a batter-runner who receives a base-on-balls. … Even a batter who is walked is permitted to overrun first base without liability to be put out, as long as he or she returns immediately to the base.