I don't understand your argument. Here is what the defense team wrote in the FM. The idea that the man seen walking by SC would have blood on him is likely supported by this statement by the FBI's search for RL:
(snip)
"Because of the nature of the Victim's wounds it is nearly certain the perpetrator of the crime would have gotten blood on his person/clothing."
DELPHI: Memorandum in Support of Motion.pdf
www.scribd.com
Pg 24
(snips)
"The evidence will also show that Liggett just flat out lied about what he (Liggett) claimed Sarah Carbaugh told him in 2017 concerning a man walking down the road near the murder scene. For Liggett’s timeline to work, Liggett needed Sarah Carbaugh to describe a man walking down the road wearing a blue jacket, who had blood covering his clothing. However, in 2017 Sarah did not say these things. This did not prevent Liggett from affirming under oath that Sarah Carbaugh did say those things."
"In fact, what Sarah Carbaugh actually told Liggett in 2017, was that she (Carbaugh) observed a man walking down the road wearing a tan coat whose clothes were muddy. Nowhere did Carbaugh claim in 2017 that the man she observed was wearing a blue coat. Nowhere did Carbaugh claim in 2017 that the man she observed was wearing bloody clothes. Nowhere. This truth about what Sarah Carbaugh actually told Liggett in 2017 blows up Liggett’s timeline, which is the likely reason Liggett failed to include this information in his affidavit."