[Dakota]

When the FLEX bats for the DP, the DP has left the game. When the DP comes back in, it is a re-entry for the DP. If she leaves the game again, she is done.

IOW, you are correct.

The following comment refers to your saying this was not a sub. It actually is a sub for DP, but not for FLEX.

This move has no effect on the FLEX player, but it does affect the DP player - IOW, the DP was "sub-ed for" by FLEX, but the FLEX did not enter as a sub.

When the DP re-enters, she has used up her re-entry rights, so if she leaves again, she is done. But even though DP re-entered, the FLEX still did not leave - she just went back to defense only.