It's not a last-man-to-help scenario ... on that side, it's quarters so it's match man. the RCB has the #1 guy ... the next guy would be Johnson's ... but the question is if they should have passed off the #1 or if Spoon was supposed to be locked.
Either way, one of the two, has the final #2 receiver vertical, in this case it's a RB and it's a wheel ... but the same rules apply.
My best guess is miscommunication but Spoon looked like he was locked on the #1 so Johnson should have probably stayed home ... but it could be other way around. Spook should have passed the #1 recer to Johnson and he stays home for any vertical route.