like i said im not sure but kick i guess would be the wrong word for it. catch would work better. like i said above if a wheel on your car catches something the car pulls toward the object that slowed the wheel down not away from it. so if a blade catches hide the blade gets slowed down and even slower while opening but the rest of the arrow is still traveling at a faster speed which should turn it into the object. its just my idea no evidence to support it but just a thought. id think that big cutting blades though would be more likely to kick it out but i dont really know.

Think of it this way. With an expandable if a blade contacts the deer before the tip does the deer is more or less a stationary object thats not going to give. The blade meets that object and somthing has to give either the arrow or the deer. Im not going to get into a physics lesson but the deer isnt going to give so the arrow must. Thats why it kicks outwards. That blade that catches must push away from the arrow to fully deploy and doing so its not going to move that deer so it has to move the arrow.

Very simple physics. Every action has an equal but opposite reaction.