So now Batman investigates (apparently accidental) train wrecks? In broad daylight? In (apparently) Metropolis? The guy needs a life - you'd think he'd have more than enough regular crime to investigate in Gotham City.
Criminal: (spotting the League) Uh-oh. Longjohns at 10 o'clock.
Hawkgirl: Well, that was pretty darn sloppy.
Green Lantern: Sorry.
Character bio: Metamorpho
Wonder Woman and Flash do not appear in this episode - Martian Manhunter appears but has no dialogue.
Although not identified as such and only seen from the back, one of the reporters interviewing the NSTB inspector appears to be Lois Lane - note the distinctive purple dress and black hairstyle.
The train wreck in this episode was originally a plane crash, but was changed due to concerns over the 9/11 attack.