Why stop Ian McEwan from getting honoraria?

The US immigration people (insert ugly descriptors here) stopped Ian McEwan from entering the US, then later issued an apology. I don’t get the reason, however. The AP article said,

**McEwan, author of the best-selling novel “Atonement,” was trying to board a plane March 30 at the Vancouver, British Columbia, airport for Seattle, where he was scheduled to speak before subsequent engagements in Portland, Ore., and Pasadena, Calif.

An American inspector kept him from boarding the plane on the grounds that the speaking fees McEwan was to receive for his appearances – $5,000 in Seattle alone – were too large to qualify as honoraria.**

Questions

  1. How would they know how much money he was to get? How would they knew what he was going to do at all?

  2. Why would they care?

  3. If they care because he doesn’t have a work visa in the US, and a speaking engagement counts as work, isn’t it still true that one can go on a “business trip” to the US and get paid for services rendered?

  4. Will he owe tax on the $5000, since it was earned in the US?

Thanks for your help here.

BTW, they apparently later changed their minds and made an apology. I guess it helps to be famous. Ashcroft has special facilities for you to visit if you’re not…

Because he told them.

http://www.ianmcewan.com/visa-2004.html

From one of APBs links