Is it still kindness if it pisses you off?

This is a question which did not even cross my mind until my journey into kindness began one week ago to the day. Case in point today we picked the kids up after school and drove 50 miles to Birmingham where all three were due at a casting. It was past five o' clock by the time we set off for home. The kids were tired and hungry. Alas the traffic on the M6 was typically rush hour and the going was not rapid. Stop start traffic winds me up and my overall state of mind was poor getting poorer. Sometime later we reached near home and as the children had been eerily good, we bowed to their wishes and detoured to the local McDonalds drive through for a heap of Happy Meals. After placing our order we moved from the first window to the second. The order was taking some time to compile but to be honest I was in a semi-daze and didn't really notice, when I was interrupted by the man in the car behind sounding his horn and making mad waving arm gestures at me. I presumed he was pissed off that we were taking so long so I ignored him. I concluded that I had every right to stay exactly where I was and I was not for moving. I then spied him open his door and come towards me. The nature of drive through etiquette dictates that the drivers window is open so I assumed that I was going to have some kind of face off and to be fair I was prepared. He reached my window and I was ready. He looked in and said "Sorry to bother you but I wanted to let you know that your rear brake light on the drivers side is not working." I looked at him, kind of nodded and looked away. He the walked back to his car and got back in. The overriding words going through my head were PISS and OFF. The order finally arrived and was distributed and we drove the short distance home. After the kids went to bed, my thoughts turned to musings on kindness when I suddenly conceded that Drive-Through-Man might actually have been trying to engage in an act of kindness. I suppose the repercussions of not having a working brake light were worse than if they were both working. I suppose that he had nothing to gain from telling me that it wasn't working and he was only trying to help. I suppose that because I was a bit wound up from the journey, I thought he was just trying to gain smug points at my expense, all of which leads me full circle to my opening question. Is it still kindness if it pisses you off?