True - if a weapon is used. A fist is (quite literally!) already in hand, however, so if I want to start a brawl by sucker-punching the guard my punch should go first. Ditto a short verbal-only spell in some cases. and ditto again if it's the opposition trying to do the same to me/us - it works both ways.
Another situation where this often arises is ambush, where someone wants to open proceedings with a sniper shot (or a spell) from concealment, where that person's concealed or hidden status has already been mechanically established.