I've run into knots in some Bernat yarn but never yet in Red Heart.
That same Bernat yarn (denim-rag: a two color twist) also had a skein with clumpy, lumpy sections where the rag color was twice the thickness or more compared to the other color.
Do you cut out the bad section and do a join or just work it in and hope for the best? I got tired of joining after cutting out bulging streaks and just continued on with out more cuts and joins. It was a poncho and no one has noticed it.
But getting a knot in the middle of a skein is so uncool.