The shadow in Panel 2 is a bit off. Remember--a tin can, from the front, is a lot like a rectangle. While the edges will curve away, rather than stop abruptly, they'll do so at the same rate up and down the can--the triangle-shadow on him would be difficult, unless there were a cone in front of him that was casting the shadow. If he was backlit, as I expect . . . it would probably be a rectangle of shadow that went almost to his edges, then spread in a triangle on the floor like you've already got.
Get a tin can and light it from the direction you're aiming at, that should give you a good idea. :)