I read in one of the posts (https://planetside.co.uk/forums/index.php/topic,28363.msg281568.html#msg281568) (https://planetside.co.uk/forums/index.php/topic,28363.msg281568.html#msg281568) that Path Tracer does not have the line issue with DOF and GISD, but apparently it's still there.
First saw it in a snow render with DOF applied. Standard render had the line (not when DOF is off), but Path Tracing has it too.