Mirana Starstorm multiple times ?! Puck waning rift damage too much ?! - Dota2 cheat ? What happened ?

Just read this on Reddit.  Apparently currently there is an exploit where a player can multicast spells and deal a great amount of damage to the enemy team. Take a look at this combat log.

This is STARFALL

Here is a few screenshots I took from his Puck game.

Look at the length of the white bar. (He has not casted Orb yet.) The amount of damage he dealt is..

and he dealt damage to Necrolyte twice with Wanning Rift in the same second.

Rumors said that this exploit is made by abusing the new change involving Quick cast. Casting without having to use your mouse to click (meaning you just have to put your cursor over the target) 

Let's hope valve fix this ASAP and ruin as little games as possible. Currently it only works with AoE spells that dont need a target. (Wanning Rift, Starfall) and they need multiple couriers to use it. So if you see someone getting multiple couriers most likely they are glitching . 

If you see anyone glitching / exploiting bugs please report them !