He did however get baptized.
Actually technically it wasn't a "Christian" baptism, it was a Jewish Mikvah. A "Christian" baptism requires the use of the Trinitarian formula. Since John did not say: "I baptize you in the name of the Father, the Son, and the Holy spirit." only a washing occurred. And yes the Greek word for washing/ wetting is baptisio, that does not negate the fact that no Trinitarian formula was used. Actually the Greek word baptizo means to dip, submerge, to immerse according to strongs and word helps. So the catholic version of sprinkling is not correct.
You gotta go under the water.
I have a friend that is an old time SBC preacher and he and I were discussing baptism. I asked him if it counted if you got wet up to your knees. He said nope full immersion.
I asked if it was okay just to get wet up to your waist. Nope full immersion. IO said okay how about up to the shoulders. Nope the Head has to get wet he said.
My reply was: So the Catholics are right just getting the head wet.
On a serious note. Read the Didache, it tells of the various accepted methods.