That is logical. If a runner possesses the ball, steps out of bounds, even if the ball is still in thee field of play, the play is dead. It follows logically possession or not.
70,040 people attended Monday according to pro football reference, might be simply based on sales...don't know. They will have zero problem filling 62k seats. Looks like they may have accounted for that large group that just doesn't want to be outdoors anyway.