Another Scenario: Can monster be targeted?
TL;DR Yes

Please have a look at the below given sketch. The line through the upper right corner A = (1,2) of the ranged Hero and the bottom left corner B = (3,0) of the monster is described by the equation y = -x+3. This line doesn't intersect any of both given obstacles since for any x &lt; 2 the corresponding value of y is greater than 1 and for any x &gt; 2 is smaller than 1. Hence, the solely common point is C = (2,1). Since the line (quoting "Line of Sight" (page 12) from the Rules of Play)


  only touches the corner of a blocked space (without passing through the space itself ), the target space is in line of sight.