Hm. The wording in LASORS is not 100% clear either way. If you are planning it, I would definitely go for 300NM distance between airfields to be on the safe side. Would only include dog-legs if I had it from the CAA that this is acceptable.
BTW, you can fly from A to B to C so you don't have to return to A to qualify, as long as the A-B-C distance is 500NM. That sorted me out - I had several 500NM A-B-A return trips in my logbook, but on a !!!!ty day I had to divert due to weather so it became A-B-C and satisfied the "two airports away" condition.