Jeremiah 38: can a gentile be more reliable than an Jew official?

In Jeremiah 38:

1 Shaphatiah son of Mattan, Gedaliah son of Pashur, Jehucal son of Shelemiah, and Pashur son of Malkijah (...)
8 ... took Jeremiah and threw him into the cistern of Malkijah the king’s son that was in the courtyard of the palace guard. They lowered him down with ropes. There wasn’t any water in the cistern, only mud. Jeremiah sank into the mud.

These Jews were afraid that Jeremiah would weak the soldiers morale, so they threw him in a cistern to let him die there. However:

7-9 Ebed-melek the Ethiopian, a court official assigned to the royal palace, heard that they had thrown Jeremiah into the cistern. While the king was holding court in the Benjamin Gate, Ebed-melek went immediately from the palace to the king and said, “My master, O king—these men are committing a great crime in what they’re doing, throwing Jeremiah the prophet into the cistern and leaving him there to starve. He’s as good as dead. There isn’t a scrap of bread left in the city.”

Ebed-melek, the Ethiopian, decided to save Jeremiah; so he asked the king to intercede for him.

10 So the king ordered Ebed-melek the Ethiopian, “Get three men and pull Jeremiah the prophet out of the cistern before he dies.”

11-12 Ebed-melek got three men and went to the palace wardrobe and got some scraps of old clothing, which they tied together and lowered down with ropes to Jeremiah in the cistern. Ebed-melek the Ethiopian called down to Jeremiah, “Put these scraps of old clothing under your armpits and around the ropes.” Jeremiah did what he said.

13 And so they pulled Jeremiah up out of the cistern by the ropes. But he was still confined in the courtyard of the palace guard.
Ebed-melek saved Jeremiah's life. The king had some interest in Jeremiah's prophecies. He went to Jeremiah

The king was interested in Jeremiah's prophecies and meet him in secret. Jeremiah told the king to surrender, but the king replied:

19 King Zedekiah said to Jeremiah, “But I’m afraid of the Judeans who have already deserted to the Chaldeans. If they get hold of me, they’ll rough me up good.”

It seems that Zedekiah had enemies that were pro Babylon, but he was also afraid of the Jews who put Jeremiah in the cistern (and were against Babylon):

24-26 Zedekiah said to Jeremiah, “Don’t let anyone know of this conversation, if you know what’s good for you. If the government officials get wind that I’ve been talking with you, they may come and say, ‘Tell us what went on between you and the king, what you said and what he said. Hold nothing back and we won’t kill you.’ If this happens, tell them, ‘I presented my case to the king so that he wouldn’t send me back to the dungeon of Jonathan to die there.’”

27 And sure enough, all the officials came to Jeremiah and asked him. He responded as the king had instructed. So they quit asking. No one had overheard the conversation.

28 Jeremiah lived in the courtyard of the palace guards until the day that Jerusalem was captured.