Sorry Gabby ,
It's very difficult to tell.

These little guys are giving you sleepless nights.
It is very difficult for WC frogs to adjust to captivity.

I'm sure you know; the first thing to do, however, is to isolate him form the others.

There may be somewhere you could have him tested: Frog Safe, Inc is a great site!
This sites also has additional information including great cleaning tips:
FDR Inc. The Australian Diseases - Chytrid Fungus Treatment Techniques

http://www.frogsafe.org.au/home/

Red leg looks like broken vessels. Sadly when this is seen the disease is far along.

If you should see any broken skin - use an antibiotic ointment, such as Tritop or Neosporin ( WITHOUT PAIN RELIEF)
I have read bad things about Reptoheal and Newskin --causing additional problems on the extra fragile skin of their inner legs.

Lynn