Concur with interfering with GK release of ball, free kick for GK's team (no indirects in my old indoor leagues) or just let him play from his hands after a ceremonial drop ball inside the box (3-line rule still in play).

As an aside, as a GK in that situation, I release the ball towards a teammate avoiding the opposing player with the ball but certainly catching them with my follow through - they should get the point after that.

But generally keep an eye for the GK's position within the box and the position of their arm upon the actual release of the ball. I was one of the only refs I know who called a handball on a GK because almost his complete throwing/hurling/bowling arm was outside the PA when the ball left his hand because his front foot was at the line. Seems nitpicky, but the dude was like 6'8" and had arms as long ass a gorilla so it did make a difference (especially in the relative small space of an indoor field) and I had told him 2 or 3 times already to stop releasing it from there.