When shooting flaming arrows into the distance, the arrow will seem to get stuck in the sky sometimes, and a 'ghost' of the arrow will reappear in the sky...
May be due to the infinity bow.
(edit : this also happens with a regular bow, without enchantements, but it may be harder to notice without flaming arrows.)

When shooting mobs with arrows, the arrow will appear to bounce off the mob, but will do damage. It's not supposed to bounce off mobs.