Funny when that guy that predicted the end only a few years back in the states was in the news, my Jw mom was rolling her eyes and laughing about how moronic he and his followers were. I cautioned her not to laugh to hard because Jws did the same thing, 1870's 1914 1925 (ancient worthy resurrection) 1975. That guy was not very different and the look on her face was sadly priceless. Like huh? It hit home but dissonance hit back and she went back under the spell.
I think you're talking about Harold Camping. I had a similar experience (though it wasn't intentional) when I and a few others were joking around arrogantly (as JWs often do haha) about how obviously wrong he was. "The bible says no man knows the day or the hour!" etc etc. One older woman said "I don't think we should be joking around about that. A lot of people are still sensitive after what happened in 1975." That sentence was probably one of the top 3 things that led me to eventually look at apostate sites online. When they rehashed the new overlapping generation, I couldn't get the question out of my head "How are we any different than Harold Camping?" That's a question that can't be answered honestly and leave you still wanting to be a JW.