Scott - relax. I don't think anyone thought you were rude, nor that an apology is even worth thinking about.
TBO is not a native English speaker, and my best guess is that when he said 'rude', he really meant something more like a 'crude' (rough, approximate, not very specific or detailed) description.
No offense taken here. I think they're pretty amazing myself, and it's a fascinating process.
-Bob
(PS welcome, if we haven't been through that yet)