made basket at wrong end

[JugglingReferee]

A player (A1) throwing the ball through their opponent's basket does in fact award two points (and only ever 2 points) to the opposite team. The individual credited for the two points is of no significance to the officials. A would then take the ball OB for a throw-in, with full endline privileges. The clock keeps going.

If you can get everyone on the same page with no hiccups, then go for it.

Since everyone is likely confused, it's good practice to stop the game, verbalize what happened and how we're continuing.

Edit: In Fed, the object is to score on your own basket. In FIBA, the reverse is true.