Out of bounds call

[random]

A1 saves a ball heading out of bounds and hit B1 who was standing out of bounds. I was told that it would be B1's team ball because B1, already established out of bounds, is considered out of play as if he were a pole or a bench. I continued, if that's the case, couldn't B1 contest and prevent A1 from saving the ball, and the guy said B1 cannot interfere with A1 saving the ball because B1 is "out of play" and such an offense is "a flagrant". Could someone clarify this? Thank you, gents.