Is this the same frog?

[jnb]

I know nothing about frogs and I guess that's why I am posting. In short, as these three photos of the same frog? I think this is a pig frog and I am not sure of how much variability there is between individuals, so I don't know how hard/easy it is to identify individual frogs. I want to know because every morning there is one frog in my pool. Never two, never zero. I take the frog to the corner of my yard (40-50ft) and let him go through the fence hoping he will return to a pond about 50 ft. further on. He would need to cross the yard and find the small hole in the screen around the pool - I live in Florida where most pools are screened in. Today I took it outside the screened in area and about 10 ft. away from the small hole in the screen. I go inside and watch him hop along the screening until he gets to the hole, goes in an hops straight into the pool like he knew exactly where he was going. So, what do you think?
Click to see larger photos - he is on a pool vacuum hose if you're wondering.

[ConVexity]

Looks like it