Let me restate your scenario. A1 throws pass to front court. B1, in front court, tips pass, tipped pass deflects off A2, in front court, toward backcourt, and then A2 (or any other A) retrieves in backcourt.
This is a violation.
1. A had team control
2. Ball had front court status
3. A was last to touch in front court
4. A was first to touch in back court
Remember, the tip by B does not change the fact that A has team control. B must have player control to achieve team control. A has team control up until a dead ball or until B gets team control. So even though A does not have player control, A has not lost team control.
Variations on a theme
If A2 is backcourt when the tipped ball deflects, no violation - A2 was not last to touch in front court, B was, condition 4 not met.
If neither A nor B are front court, no violation because ball never had front court status, condition 2 not met.
If B ever touches ball after A2 deflects and before A retrieves in backcourt, no violation, because either condition 3 or condition 4 were not met (depending on position of B at time of touch.
However, if A1 passes in backcourt (can even be toward A3 also backcourt), B is in backcourt and tips A1's pass into A2 in front court, then A2 steps backcourt to retrieve, you amazngly still have a bizarre backcourt violation because all four conditions above were met! Just one last fun variation
