It could hardly lead to a true conclusion (5,5)
I believe the answer is:
false start
'it could hardly' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'lead to a true conclusion' is the wordplay.
'lead' becomes 'start' (I've seen this before).
'to a' says to put letters next to each other (I've seen this in other clues).
'true conclusion' becomes 'false' (I am not sure about this - if you are sure you should believe this answer much more).
'start' put after 'false' is 'FALSE START'.
Can you help me to learn more?
(Other definitions for false start that I've seen before include "In which someone jumps the gun" , "Unsuccessful beginning" , "may lead to total recall" , "In which runner is seen to have jumped the gun" .)