So you haven't confirmed anything, but felt the need to post about nothing? Right, just checking.
I haven't tried in 4.3, but in 4.2 I often found that trying to use 2 launched traps in a row would result in trap launcher not being ready yet and the second trap being planted at my feet because I'm used to things having a 1 second GCD (particularly on beth'tilac while killing spiderlings), and I suspect many people can relate to that frustration. Because of this, I think launching a trap incurs a 1.5 second cooldown on just trap launcher, since trap launcher doesn't activate but the trap does drop.
Edit: I guess it's also possible that I'm hitting the trap launcher button slightly before its cooldown is finished and the trap itself slightly after, causing the launcher to fail and the trap to drop even though both have the same 1.5 second cooldown.