Laguna acting as seifer

[Skyblade]

I'm just wondering how did laguna knew that technique?
Laguna and Seifer haven't met in the past right?

Actually, this has been brought up before. I will reiterate my explanation:

Laguna said that he hadn't wielded one since basic training. This would imply that gunblade use is at least briefly explained in the G-Army basic training. The stance that the G-Army teaches is probably a fairly standard gunblade stance (it is also probably one of the easiest to learn). So it is the same stance that Seifer uses. Squall uses a different stance. Assuming that Laguna and Seifer are the only two people to use a particular stance even though Laguna said he was taught in basic training is silly.

The main problem with the movie idea is that the camera man ran away before the combat between Laguna and the Dragon actually began, so Seifer couldn't have seen Laguna fight in the movie.