@hayhor That's unusual then. I'll have to test it again.
But here are some patch notes I pasted:
Interception Pylon.png Interception Pylon: The Pylon is now significantly more aggressive in the way it shoots down grenades. Rather than just identifying between incoming and outgoing projectiles, it now predicts the trajectory of grenades thrown within the interception zone and intercepts them if they will land anywhere within that zone. This means that no grenade can contact any surface within the interception zone regardless of the team, but players can fire grenades outwards from anywhere within the zone.
That was from December, the last update that really changed one of Wattson's abilities.
As you can see, it states you can fire grenades outwards (from anywhere inside or outside), as long as it isn't predicted to land inside it's radius.