No, he's skirting that - he's saying all fetuses are 'potentially' human beings, and therefore should be protected.  It's a junk argument.  At least it's a junk argument against abortion. It's a pretty good argument for setting up a dna bank or whatever.
Yes, that is a stupid argument, because all living human beings are living human beings and should have their rights as a human being protected by law.  "Potential" nothing.  
Every human being potentially ages another day when they aren't killed or die a natural death.
Pearls before swine, of course, as you distinguished mentally-challenged fellows don't know the difference between an organism and an orgasm.
You're a cretin.  The point was as you say:  that potential is insufficient - that there must be something 
else about a fetus (or in addition to) that makes it worth preserving, if it's worth preserving.  That's why the argument was a non-starter.  I deliberately left it open as to what 
does constitute a creature worth moral consideration, and how much it's due.  You have not the slightest idea what I regard as morally important, maggot, so spare me the chest-puffing indignation.
Also, 'human being', as distinct from 'human' is a label best-reserved for humans with an actual mind/intelligence.  It's synonymous with 'person'.  Not all fetuses meet those requirements - early-stage fetuses are as much 'beings' as crabgrass is.  I mention this in the interests of clarity and honest discussion.  You are not entitled to that little rhetorical punch, so can it.