I'm not English speaker so sorry for my writting faults if there are any.

Related replay:5362990983
But surely this is known bug. Here is a post suggested this: https://dev.dota2.com/showthread.php?t=124118
I do some tests above this bug and get some conclusion. If a hero has Projectile Speed, all works will fine. But most melee heroes don't have Projectile Speed, if they pick ability which can perform ranged attack, such bug appears. A few of melee heroes have Projectile Speed(eg. Dragon Knight) because of their skills, they don't worry about this shit.
Take a step forward, it's known that such abnormal attack has 0MS, therefore projectiles will stay at spawn point forever. A funny fact is these projectiles won't despawn, like a ghost projectile, ignoring attacker or receiver has died once. An unit can be attacked by moving through ghosts. Attack damage and modifiers are set at the time perfroming attacks. Technically a player can predict an enemy hero's moving and set as many ghost as he can, then bait him to get a kill, like techies stacking mines at rune. Maybe I can watch this on dotawtf before patch. Another catastrophic way is do numerous attack on land creeps. Because land creeps die quickly, those ghost projectiles become everlasting ghost, player's computer or server may crash eventually.