Over conditioning usually refers to how the hair looks/feels when there is either product buildup or the interaction between two (or more) products give undesirable results.

Situations that I am aware of for over conditioning include the following:
1.  Conditioners with -cones build up on the hair.  The hair will have either a greasy, heavy appearance or will be "crunchy" with stiff ends.  A clarifying shampoo followed by a non-cone conditioner will usually resolve this.

2.  Conditioning with protein conditioners.  If several different protien conditioners are used, these can interact and cause "crunchy" ends.  Clarifying will usually resolve this.

3.  Using -cone products and some oils will also cause those "crunchy" ends and a good clarifying will also resolve this.

Generally speaking, if you use heavy conditioners, a vinegar rinse used frequently, can help minimize product buildup and reduce the need for a harsh clarifying shampoo.

Yep - I think you are probably in pretty good shape.  But, at the first sign of crunchy ends, take the time to clarify.