"There’s no bad news or good news. There’s only news"
- Master Ogway, Kungfu Panda :)
Some people might think interview in CCIE lab is difficult. Some people think the opposite. And I'm one of second group. I can say this out loud because I did the 2-day CCIE lab, with interview after the first day and troubleshooting section to explain what I did, how did I find the problem, which debug command I used, two times.
For those who are in doubt about their English, think like this: I believe all CCIE proctors are aware that not everyone is native speaker. So even they decide to conduct a real interview in the lab, I guess they don't expect the candidates to have a perfect English. What matters is the ability to communicate the keywords. And with one-to-one interview that I had back there in 2001, I could use the white board drawing to put more explanation.
More drawing, less talk.
For me, it looks easier then explaining the answer in detail in writing. And again, I have done it that way. My CCIE in Routing and Switching track is the witness.
If you think writing the answer is easier, well, it depends. I know many engineers out there who don't like to write documents, who don't like to write long emails. And yet they still exist. Just as some guys I know who like to talk and explain in white board, but not writing it in detail.
Good luck, anyway.