And this mistake of trying to be ultra-secure, without understanding change addresses, is a classic way to destroy BTC. It also bit someone for 7208 BTC way back in June 2011:
https://bitcointalk.org/index.php?topic=11104.0;all
That 7208 BTC would be worth about $680,000 today.
There will be a lot fewer than 21 million BTC in actual usable existence after all these errors are tallied!