You missed an apostrophe there.
"If a pokémon is switched out, the round ends immediately thereupon.
If a pokémon u-turns or baton passes out and there are any pokémon who have yet to move that action, they perform their attacks, with any that had been targeted at the u-turning/passing pokémon striking the new switchin instead. The round then ends immediately at the end of that action"
"If a pokémon is switched out, the round ends immediately thereupon.
If a pokémon u-turns or baton passes out and there are any pokémon who have yet to move that action, they perform their attacks, with any that had been targeted at the u-turning/passing pokémon striking the new switchin instead. The round then ends immediately at the end of that action"