Endline Play

[McMac]

Had a play in my MS boys game Thursday night. Player was out of bounds (legally), got one foot (other off floor) in bounds then touched the ball. I was in the L and made no call. My partner in the T calls the play dead stating he was still out of bounds.

We discussed the play and we both saw the play as above. I made no call thinking you only need one foot in to re-establish inbound status. She called it because he did not have two feet in bounds. What is the correct ruling? I could not find it in either the rule book or case book.