I think where a lot of the confusion arises is that the laws have been crafted over the last twenty odd years to remove any attempts to read a player's mind and to judge only by outcomes. Hence in fouls we merely have to decide if the outcome was careless, reckless or excessive force, no need to ask if it was intentional. A purely accidental trip, if judged careless, is still a foul.
So too in handball: we are not asked if it was intentional at all...not even if it was deliberate....but rather if it was a deliberate ACT. In other words did the actual ACTION appear controlled by the player (rather than just an arm swinging in a natural position). We do NOT need to judge if the OUTCOME was intended.
So, in our OP, the player committed a deliberate act, with an unintended outcome - so it is a handling offence. If a player rushes in with two arms extended above his head, this is a deliberate act...handling. A player who is hit on the arm while merely running with arms moving...no offence.