To cut a rug means to dance in a lively and energetic way, but in this sentence Ernie is described as not being able to dance at all or dancing in a very dull manner
Context: Ernie could really not dance at all or dance in a very dull and sluggish manner back then.
Hypothesis: Ernie could really cut a rug back then.

Given this context, determine if the hypothesis is true (Yes, no, or unknown)?