Own The Pit, Not The Fire

The Gemarah says in Pesachim (6b) and other places that there are two things not under a person’s ownership but the possuk considers it in the owner’s possession.  They are chametz on pesach and the mazik of bor in a public domain.  The Tosfos Chachmei Englea asks why is the mazik of aish not included on the list?  He answers that in regard to chametz the possuk says the obligation is שלך, of your ownership and in regard toבור  it says בעל הבור, it also requires ownership.  However, for אש the obligation is on המעביר, the lighter of the fire, there is no requirement of ownership.  We see that the obligation for בור  is because of the ownership as opposed to the obligation of אש  is for making the מזיק