Bug? Linetrace report hit and set vector 0 0 0 when shooting skybox

When I do a linetrace and shoot up in the sky returnvalue is set to TRUE even though linetrace do not collide with the skybox. OutHitImpactpoint reports 0,0,0 (or 1,1,1 ?)

I guess some smart people found workarounds for this but isn’t this a bug? Shouldnt the returnvalue be false ?