Mechanical broadheads....

[Elkslayer]

It is unlawful to hunt big game animals with
a broadhead blade unless the broadhead
is unbarbed and completely closed at
the back end of the blade or blades by
a smooth, unbroken surface starting at
maximum blade width and forming a
smooth line toward the feather end of the
shaft and such line does not angle toward
the point.

The argument that makes most sense to me is that mechanical broadheads are barbed, so if you make a bad shot that arrow is going to remain stuck in there where a broadhead with a closed back end can be worked out.

This was the reason I got as well when I talked to a Game Warden.

[STIKNSTRINGBOW]

It is unlawful to hunt big game animals with
a broadhead blade unless the broadhead
is unbarbed and completely closed at
the back end of the blade or blades by
a smooth, unbroken surface starting at
maximum blade width and forming a
smooth line toward the feather end of the
shaft and such line does not angle toward
the point.

The argument that makes most sense to me is that mechanical broadheads are barbed, so if you make a bad shot that arrow is going to remain stuck in there where a broadhead with a closed back end can be worked out.

This was the reason I got as well when I talked to a Game Warden.

That was my understanding also.
Everyone can argue about all the rest of this stuff, but AT THE TIME THE RULE WAS WRITTEN, ,..... 
Archery Tackle is constantly changing, and the rules will too, after they allow mechanicals, then everyone will complain about not being able to use "pods"

[Button Nubbs]

"pods" I think pods should be allowed because it won't matter where i hit the deer, it will die! That will make it easier for me I won't have to practice all the time and I can go to the woods and just start flingin arrows! I can't believe dfw won't allow these

[STIKNSTRINGBOW]

See what I mean !   

[DBHAWTHORNE]

Heat seaking arrows with pods...thats the way to go

[STIKNSTRINGBOW]

Heat seaking arrows with pods...thats the way to go

Don't forget the lasers in the BH, and gps chip,  !!

[kibber]

I have been told the the same about the mechanical broadhead not backing out of an animal that has been hit poorly. Never tested this theory but seems to make some sence.

[halflife65]

That explanation makes sense to me.  I don't have a problem with mechanicals but also no plans to change from fixed even if they became legal.