It's good your MLer fired when called upon to do so. But leaving it in it's uncleaned condition for 3 weeks is'nt a good idea (depending on what type of Power you use?) You could have just unscrewed the BP and pushed out the load and recleaned and reloaded. Sometimes you dont see what's really going on in the Barrel with your naked eye and what looks to be fine may not be, it all adds up after repeated uncleanings.
Also I may push some of my Cleanings a tad long but I know how long I can go befor I need to do it, also the SS Barrel can take a-lot more than a regular Steel one. In the Future at least run a Patch of something like Montana X-Treme Bore Conditioner down the Barrel just to be on the safe side, it's what I do and works fine for me.
Best of Luck to You!
(BP)