Under the Controlled Substances Act, "if death or serious bodily injury results from the use of" an illegally distributed Schedule I or II drug, then the distributor of that drug faces a twenty-year minimum prison sentence. This "results from" penalty enhancement has been susceptible to varying interpretations among the courts. Recently, in US v. Smith, the US District Court for the Eastern District of Kentucky applied the Burrage vs. US framework to uphold a "results from" penalty enhancement based on an oxycodone overdose. The court was correct to determine that the evidence supported the finding that the oxycodone was a "but-for" cause of the victim's death. However, the court's examination of other substances found in the victim's system highlights a question left open by Burrage: whether the but-for causation requirement of the "results from" enhancement is inapplicable when the drug distributed is "an independently sufficient cause of the victim's death or serious bodily injury. Without such an interpretation, the enhancement may fail to apply to anyone in cases where a victim is harmed by multiple sufficient causes.