I'm not sure I'd advocate a 180 degree turn at 500 ft ish agl , having gone IMC, in an area such as this accident! A perfectly flown rate one turn at 100 kts will take up about 1 mile laterally, and it's unlikely to be that well flown so probably will use up a lot more space which the map would indicate isn't there to be used.
The notion that the 500 ft rule should influence your decision making (as quoted by a recent post) is something that should be more accurately taught during the PPL, by the sounds of it. The aircraft and its occupants' safety is paramount at all times, and the last thing a low hour PPL (or indeed anyone) need concern himself with facing a letter box in a valley, is Rule 5.
If you get yourself into such a situation, just thank your lucky stars that you are not in a Cessna 152 or similar, and find a spot to land.
Maybe a sensible addition to the PPL syllabus would be some form of bad weather flying awareness exercise, done somewhere like the Lake district or Wales. It may emphasise to the student how unforgiving an environment it would be to get stuck in IMC. It would be at least as relavent as the instrument awareness training, maybe more so. By definition, you are not likely to inadvertently go IMC at a sensible cruising altitude; it is most likely to be below MSA in high ground.
CFIT is still the world's largest cause of accidents across the board, the more aware you can be of that and the causes, the better.