Continuity mistake: Mike yells at Jessie to make himself useful and find a gun. The shadows in these two scenes are very long indicating it was shot late in the day. In the next shots and rest of the sequence, the sun is overhead.
Continuity mistake: After Gus goes to the restroom, there's a shot of the cartel leader smoking a cigar as he turns to look at Jesse. The cigar is burnt down nearly to the band around it where his fingers are. When it cuts to a different angle to him taking it out of his mouth, suddenly there is much more cigar left above that band.
Continuity mistake: There is an X on the back of the black Hummer during behind shots. It disappears approximately 10 seconds later.
Continuity mistake: While Gus speaks with Eladio beside the pool the sun changes on the floor between shots.
Answer: Saul is a criminal himself. It's not past his capabilities to forge some documents to show the 857k is available.
Ssiscool ★
Forged documents by Saul is most likely the correct answer.
The_Iceman