The call to the JLA about the Titans isn't something that Batman answers directly or even acknowledges: as one might anticipate, he simply acts. Using the Watchtower's teleporter (and a newly designed method to work its controls remotely), the Dark Knight has arrived at the lab with but one thought on his mind: to get to the bottom of this.

Thus, while the more visible members of the Justice League are moving in to take control of the situation, Batman is covertly entering the labs to find that situation's root cause and eliminate it. It's how he works.