At the miles you got it probably needs a new clutch especially if its the stock clutch with the riveted plate. They will let go and some times its not pretty.
I've got an energy one with a 15% stronger spring. It eliminates the stock riveted plate. Look up in the sticky section and check out the extra plate clutch kit write up.
Do the Sportsters have a two piece pushrod for the throw out like the big twins? A buddy of my had these two pieces weld themselves together on a 2009 Ultra and had the same symptoms. I've never had a sportster tranny apart so I have no idea. Just caught my attention since symptoms were so similar.