Yes
There is a JW I have not seen for about 10 years but who has occasionally e-mailed me. Just before the pedophile issue came up he discovered that they had one in his congregation. He was an Elder as well. Seems the other Elders had kept in from him. Not sure but even think the pedophile was a Min Servant. My friend informed London Bethel. They sent couple of heavies up from London. Sorted the Elders out removed the guy from being an MS, not sure if they DF'd him as well. But the consequence for my friend was that the other Elders stopped talking to him. In the end, the last I heard, he stopped going to meetings. But he was one you would never thought would leave.
Another JW Elder brother again concerning the pedophile issue. It was after the Panorama program here in Britain was broadcast. He asked other Elders about the subject and whether the "two witness" policy was true. He was told it was. I believe from what I was told he now "hates the JW's with a vengance". Again this was a guy who when I met him many years ago, was a pioneer, the "perfect JW".
Last year I met a guy who came to our church his family mainly JW's. He asked if I knew his brother had left, shocked I said no. It seems his brother had been digging into WT teachings etc. Come across all the stuff we know so well. Decided that all his life he had been living a lie. He was either in his late 30's or early 40's. Had dedicated his life to being a JW had decided not to marry and pioneered. Was a MS when I last knew him. Again someone who you would never think would leave.
Now recently I was in church one Sunday three weeks ago. We had sung a couple of songs then the Pastor asked us all to say hello to those around us. As I was standing speaking to people. I looked across the church and spotted a guy. It hit me like a punch, he was a JW Elder last time I knew not so long ago. In fact he was the guy instrumental in me becoming a JW. All through that service I kept trying to sneak a look at him. Then at the end I tried to get to him but people kept wanting to speak to me. By time got to where I last saw him he had gone. He has not been back since, I hope he will. But is he is still living where I last knew, he is quite far from the church.
But all this shows that we can never say that such and such a person will never leave the Watchtower. Given the right incentive,information or something happens in their life there is always that chance. We must be ready to help them.