Way to intentionally ground legally?

[NJOfficial]

I guess I see this as similar to a play where a runner, in the process of being tackled, intentionally "fumbles" the ball forward to a teammate. The term "throwing" seems to apply equally to both cases, and the ball certainly travels in flight. If we rule that play an (illegal) forward pass, then I'd say we should rule this a forward pass and therefore intentional grounding also.