So potentially could have violation (for being out of bounds illegally), then a technical foul afterwards if there is a delay returning in bounds?

In the situation I described, a member of the throw in team leaves illegally, returns in bounds a few seconds later to receive the throw in, the team is whistled for a throw in violation and they lost their alternating possession. Is that a correct ruling?

No. The violation would make the ball dead, so there's no technical foul.
The technical foul is for delaying the return after being OOB "legally."

In the situation I described, a member of the throw in team leaves illegally, returns in bounds a few seconds later to receive the throw in, the team is whistled for a throw in violation and they lost their alternating possession. Is that a correct ruling?[/QUOTE]
Yes, the ruling is correct. The arrow flips when the throwin is complete. The throwin is complete when the throwin team violates.

Yes, the ruling is correct. The arrow flips when the throwin is complete. The throwin is complete when the throwin team violates.[/QUOTE]

Thanks!