Hey Steve,
Joe's in Dayton is NOT some fly-by-night Triumph start-up/part time dealer. You EITHER got a reply from the "Dick-of-the-day" toad (bad one's slip in everywhere), OR, MAYBE they thought you would rather take care of it yourself, IF it really is that minor of a fix, instead of the inconvenience of having to bring it back to them.
WD40 SHOULD not do any harm to paint (if it's factory paint), but you can place a rag over the fender until your through spraying it, and then wipe off any extra on the fork tubes/legs.
Now IF your uncomfortable doing this yourself, or if you feel it's their responsibility (AND IT IS!), or if you feel it could be something more serious (and it could be) take it back and talk to the tech. BE NICE, as people have a tendency to respond in the same manor as they receive.
I know Moe personally, and there just aren't people as nice as him in life, so let me assure you, he meant well. Sometimes, the typed word isn't received the same by all.
Keep us posted on the situation, and best of luck.
