Suggest Treatment For Persistent Shoulder Pain

I am pretty sure that one of my coworkers is attempting to fake an injury in order to keep from having to lift heavier objects. I have a background in athletic training and sports science but wanted to make sure that his symptoms make as little sense to you as they do to me. Initially he experienced pain from forced hyperflexion of his shoulder. Due to this he was having some mild pain during overhead movements (flexion and abduction). He claimed that he was experiencing no more pain in the shoulder and was planning on resuming normal work activities on Monday. However, he helped someone lift a television (around 100 pounds) which caused more shoulder pain. I had experience several times through the years that forced hyperflexion can cause a shoulder sprain that needs a few days of rest, NSAIDS & ice but no lasting issues. I do know that athletes who do a lot of overhead throwing can gradually damage their labrum allowing a sprain or tear during forced hyperflexion but he claimed that this was not the case. He refused medical care so he was allowed several more days off work and still was only experiencing pain during overhead motions and none that would constitute a shoulder separation or labrum injury. Once he was told that he could have a few more days off his symptoms started to decrease and showed a recovery timeline that would have put him back on regular duty on the day he was supposed to come back. When he arrived at work that day he proceeded to inform us that his shoulder was completely better to the point that he was comfortable and able to weed eat for two and a half hours. While weed eating he initially claims that he slipped in a ditch and used the trimmer to catch himself pushing down at 45 degrees between extension and adduction. His pain is still only in his shoulder at about 120 degrees of abduction. None while crossing his arm over his chest. None during internal or external rotation. And also none during hyperextension. He says there is pain when he first wakes up that then goes away just to gradually get worse as the day goes along. His pain is from the intermediate area of his trapezius muscle and supposedly runs to and across his clavicle. A member of the management staff was trying to get him to retell exactly how this had all played out. Upon review the television now was around 150 pounds and when he slipped while weed eating he fell all the way down striking both elbows (bent) while his shoulder was in hyperextension. I have exhausted all of my resources attempting to find out what injury he might have that causes pain in this particular area but only during one motion. Any help would be greatly appreciated. Thanks!