Throw-in confusion
 

Many lines on the court, one of which is parallel to the end line. After a made basket by Team A, Team B goes to inbound but instead of going behind the end line, goes behind another line he obviously believes to be the end line and passes the ball in to a teammate. No pressure by Team A. It's not an immediate violation, but it's not a valid throw-in. At what point does it become a violation? Or, upon recognizing the mistake by Team B, do you just blow the whistle and let them re-administer the throw-in behind the correct end line? Would you treat this differently if there were pressure by Team A?

Purpose And Intent, No Citations, Common Sense ...
 

Even if the old, grizzled veteran referee said, "Black line all the way around".

(I hate that.)

Early in the game, visiting team, re-administer.

Just once, only once, and tell that to the coach.

Home team should know better, but I might do the same for them.

Just my opinion, certainly subject to criticism.

Fool me once, shame on you, fool me twice, shame on me.

Confusion ...
 

We have few high schools in our area that had, or still have, endlines and/or division lines that can be confusing for officials, I know, I've had several inadvertent whistles over forty-plus years.

Came across a confusing sideline in a middle school gym this past season.

The "real" sideline, only the one opposite the benches, was oddly very far away from the bleachers, and players from both teams (and me) thought an intervening parallel line between the "real" sideline and the bleachers was the line for basketball.

Parents sitting there told me, "Happens all the time.".