What:
A long throw from the sideline doesn't come back in field. Where do you set your pivot correctly and continue to play?

Result:
A defender is always in bounds when making a play on the disc (11.2). This means that if a defender touches the disc whilst out of bounds -- the disc is then played from nearest point on the central zone (11.7.2).
Note:
if a defender hits the disc but the wind takes the disc back in field - the disc is still live. Offensive players can become out of bounds (11.5). This means in the same situation if offence touches the disc first then it is a turnover and the disc goes back to where it crossed the perimeter line (i.e. was last in-bounds). (11.7.1). If an offensive player jumps from in-bounds and touches the disc before landing, then that establishes a point where the disc was in-bounds. If this results in a turnover ,without the receiver ever establishing possession, the disc will come into play at the point nearest to where the offensive player touched the disc. If the receiver catches the pass and throws it while in the air, and the disc lands in-bounds, then that establishes the disc as being back in-bounds.

Note:
If players who had good perspective on the play cannot agree on where the disc went out-of-bounds, the mid point between the two proposed locations should be used.
Extra:
If a defender jumps, intercepts a pass, and then lands out-of-bounds, this is not a "double turnover" - the defender still retains possession.