The hydra... (Spoilers)

There's something that I don't get.

When the hydra appears during Iolaus's retelling of Hercules's labors, it's a genuine monster and Hercules fights it by himself. Later, in a flashback, it's revealed that the "hydra" was actually a group of bandits(?) disguising themselves as snakes. "The masks of serpents. No wonder men thought they were monsters." Then, in the closing credits, we see Hercules's team helping him to defeat the genuine monster.

So, is the hydra a genuine monster or not? I get the feeling that the CGI in the closing credits was an afterthought. It creates a continuity error when they reveal that the hydra wasn't really a monster, but then later reveal that it was a monster brought down by a team instead of Hercules himself.