What can they do now?

[referee99]

Team A passing the ball in the front court, ball batted by B1 into back court.
A1 is the only player pursuing the ball, near the sideline in the back court. A1 starts a dribble, actually toward opponents end line. Takes 2 dribbles and realizes that he is losing his balance and will soon go OOB. A1 pushes the ball to the floor one last time and then his momentum carries him out of bounds.

No other players are in the back court. A1 then regains balance, and returns to the floor. What can he now do?

Catch the ball? Resume his dribble?

Any difference if he dribbles the ball off of his leg and goes out of bounds?