Rocket, because i see/hear two explosions.
That's lag, similar to the Ryno V and Homing Rocket.
When you move projectiles around like that, it seems as if one is deleted as another fluidly is spawned to take its place
When you lag though, the initial projectile doesn't get deleted, and it may feel like more than one rocket hits the surface; don't worry, it only has the effect of one rocket.