I think your son weights 160 lbs. It is right there in the text!
Seriously, taking pictures at weird angles and poor light does nothing to help with eyeball weight assessment. People don't normally see hogs and people like that, together, such that this would even be a remotely normal circumstance for weight assessment.
In the future, just carry a measuring tape. Take a heart girth measurement. That is where you pull the tape around the hog just behind the front legs, IMMEDIATELY behind the front legs at the armpits. Pull the tape down tight enough to compress the hair. Take the number of inches and multiply by 10 and then subtract 200. So a 41' measurement would be 210 lbs. A 37' measurement would be 170 lbs. This won't work for pigs under 30 or 40 lbs or thereabouts.