As this was an unauthorised flight, perhaps the pilot thought the risk of getting back through the bad wx to save getting a bollocking and potential instructing job, outweighed the risk of the conditions. If so then he cleary paid the ultimate price. Why would you not climb above MSA, get onto control and get help if you were instrument rated. I would suggest if you didn't want anyone finding out.
Maybe the good old human factors decision making model is at work here. The get-home-itis effect. Always take some over night gear with you on a x-country cos you never know what might happen. I know a few guys that have been stuck in the middle of nowhere and decided to stay due wx. Might have got some grief but lived to move on to bigger and better things.
And I'll thrown in my agreement with remoak too. There is no experience in aeroclubs (on the day to day flying level generally). Fresh outta school instructors with no experience themselves can't teach what they don't know.