friend fell through the end's obsidian platform

My friend was giving me a tour around his world and he showed me the end portal. This is a very large world with a lot of buildings and stuff. He went into the end portal so i followed. A few seconds after arriving in the end, I got the message "(Friend's username) has fell into the void." My friend had a lot of good stuff and he really loved this world. Naturally, he was devastated. When talking to him, he said he might've fell through the obsidian platform. I think since he was on it when I went through and it resets every time you go through, it was trying to reset and made him fall through. I'm not sure if this is true though.