Is a conviction based solely on inconsistent and contradictory testimony from a cooperating co-defendant legally sufficient to sustain a criminal conviction?

Due Process requires a criminal conviction be obtained by proof beyond a reasonable doubt. Cooperating witness testimony is admissible evidence, though juries are specifically instructed to give such testimony stricter scrutiny. In Mr. Pierre -Paul’s case, inconsistent testimony by a cooperating co -defendant constituted all of the direct evidence against him , including evidence of “consciousness of guilt” that not only prejudiced him at trial, but was used as the foundation for a sentencing enhancement. The questions presented here are: 1. Is a conviction based on inconsistent and contradictory testimony of a cooperating co-defendant sufficient to sustain a conviction? 2. Is the probative value of vague testimony of that same biased and inconsistent witness to an alleged attempt to influence him not to testify outweighed by the substantial prejudice ? 3. Is the same testimony , lacking content and context, sufficient to warrant an enhancement pursuant to United States Sentencing Guideline § 3C1.1?