RE(Reducing Bushing) Underground

[Goroon]

Second time iI have been asked about "Complete Runs" 300.18 (A)
No Answer!
It appears the contractor had a 100 ft run under ground, RMC 1".
Ran out of 1" halfway, put a RE inside a coupling and finished with 3/4".
Raceway fill not violated for 3/4", 8#14
Size of raceway not in spec's
No UL Book

Thoughts?

 

[Volta]

Hard to fish in one direction.

Running threads used with a coupling. That will not ensure electrical continuity.

Couplings and Connectors. (A) Threadless. Threadless couplings and connectors used with conduit shall be made tight. Where buried in masonry or concrete, they shall be the concretetight type. Where installed in wet locations, they shall comply with 314.15. Threadless couplings and connectors shall not be used on threaded conduit ends unless listed for the purpose.
(B) Running Threads. Running threads shall not be used on conduit for connection at couplings.