Funny thing similar thing happened yesterday to me at Wellesbourne.
Left Kemble with full tanks, 2 POB, in a C150 aerobat.
Landed at Wellesbourne, had tea and cake and a couple of hours later checked over aircraft..... plenty of fuel for trip home.... started no probs, taxied off grass and tested the brakes...all good... asked P2 to test brakes...he pulled the power and as braked engine cut off. Weird.
Started again with no probs and no probs on way home... though did keep a look out for suitable fields