I'm sorry to disagree with others, but NO, this is not safe. It is called "Open Kettle" canning and it's dangerous. The point of the water bath is not to seal the jars, but to sterilize the contents and the jars. 10 minutes of boiling at 212*F does that for high-acid foods.
I could take a jar of contaminated food, warm it up, put it in a hot jar and put a lid on it and as long as the lid and rim are clean, it will still seal. A seal doesn't mean it's safe. It means the decrease in the temperature has caused a decrease in the atmosphere inside the jar. It's the same reason you can take a peeled, hard-boiled egg and a jar with a small opening, drop a match into it and the vacuum with suck the egg inside. It's no different than using a FoodSaver.
Google "Open Kettle" canning. You've just gotten lucky so far. There is a reason that canning information is updated by the USDA and old practices are thrown out. Just because grandma did it that way and never poisoned anyone doesn't mean anything. Grandma also never buckled up in the car.