I'd bet on late blight. Probably changed environment such as different temperature aborted the infection on the leaves.

That said, pick those bad tomatoes & put them in the garbage. Today!

NEARLY ALL PLANT DISEASES CAN BE AVOIDED IF SOIL IS CLOSE TO BEING RIGHT....COMPOST, MINERALS LIKE ROCK DUST, ORGANIC FERTILIZER AND GOOD WATERING PRACTICE...SOIL NEEDS TO BE ALIVE AND FULL OF MICROBES AND ENZYMES ETC...AND THE RIGHT TEXTURE SO SOIL CAN BREATHE....PREVENTION IS BEST WAY....ORGANIC SPRAYING IS ONE WAY TO MAKE SURE THAT PLANTS RECEIVE WHAT THEY NEED....ROY