Oh yes, instant karma happens! Here are just two little incidents from my own experience: 1. Before retiring, I was head of the woodworking departments in a large workshop for handicapped adults here in Germany. About 17ys ago, I had an elderly lady in my team, doing the bookkeeping. As she had constant health issues, she couldn't work more than half time and thus was usually rather short of cash. Came end of the year and she received some unexpected bills, electricity/heating etc, that worried her much, as she couldn't actually pay them all. So I decided to help her and deposited an envelope with 500€ from my Christmas bonus in her home letterbox. I knew, handing it over directly would have totally embarrassed her, so I did it anonymously, just writing 'Aktion Mitmensch' on it, (i.e. 'Action Fellow Human Being', referring to a well known welfare fund raising campaign in Germany, 'Aktion Mensch', -'Humanitarian Action'- which had also contributed to our institution. Thus, she would have a clue that it was freely given to her aid by someone.
Weeks later, one of my sons, J. (14) was involved in an accident, where one of his mates got severely injured and hospitalized. It was at least partially J's fault and circumstances were so obscure and twisted that it seemed unlikely, my liability insurance would step in and pay. Shortly after, a really massive financial demand came from his mate's parents, so I quickly had to take a lawyer, who required an advance payment of 2000€. We had recently bought a house, with a heavy mortgage to pay off; I was the sole earner in the family and we could just about make ends meet then. I knew, I had little over 1500€ left on my account, and was expecting other bills too; taking another loan/overdraft was out of question. Oh dear! But what a surprise, when I looked into my online account and saw there were suddenly >2000€ in it.
How? Turned out, that I had once, long ago and long forgotten, bought a permanent lottery ticket from that very 'Aktion Mensch' that they sold for fund raising. It got automatically renewed every year and I had just won 500€! The first and only time ever!
Pure coincidence? Really? (Btw, that lawyer plus my insurance settled the whole matter later, we might have lost our house otherwise).
2. In my job, one afternoon me and a colleague were supervising the departure of our client co-workers at the front yard of the building. There was one chap, X. among them, who had some psychic issues; his intelligence was perhaps just a tad sub-standard (though still higher than 3 average Trump rallyists combined), but who also, if his world view collided with facts, could become very nastily upset. And upset he was that moment, obviously. We saw him walking off the premises towards the public bus stop across the street, mumbling and swearing to himself and being just short of throwing a tantrum. Again: Oh dear! He would cross the street, looking neither left nor right, forcing all cars to stop. Luckily, there was a traffic light on red ahead, so they had already slowed down. It was too late and distant for us to intervene; so the Guardian Angel (that these guys usually keep busy) had to do the job again. But obviously he failed to soothe X, for the latter, in a fit of rage, suddenly threw his carrier bag onto the open loading bed of a truck, that stood waiting at the red light. And lo, at that moment the light switched to green and off went the truck, bag on board. It contained everything dear to X's heart, his electric shaver, that he frequently used where- and whenever he felt like a shave during the day, his impressive weekly supply of candy and much more interesting stuff.... The expression on X's face was absolutely priceless and we nearly rolled on the ground with laughter. But X was so stunned, he forgot all about rage and temper (which we had expected to follow now) and walked over to his bus stop like a beaten dog.
Colleagues told me later, that he was very calm, cooperative and considerate the following days, so I guess, instant karma had given another good life lesson.