My Journey on Lincoln's Assassination

[Gene C]

It "could have been" someone else using Booth's name.
Or "it could have been" Cobb was pressured into saying it was Booth
Or "it could have been" the mysterious rider said "Boothe" and Cobb misunderstood. They do sound similar.
Or "it could have been" Booth was insulted that he wasn't recognized for the star matinee idol that he was, so he gave Cobb his real name to impress him.