“So Moab was subdued.” Israel got free from slavery under Moab. In the battle, however, there is no indication that Israel’s troops crossed the Jordan and went after the heartland of Moab. Israel was free from Moab but did not conquer Moab. The Moabites would soon crown another king.
“The land had rest: 80 years.” The chronology of the Judges period fits into the general chronology of the Old Testament. Men like Ivan Panin worked hard for years on the chronology and discovered that when it came to the formula in Judges, “the land had rest: 80 years,” the key to making the whole period of the Judges work was to include the years of slavery or subjugation into the full period of 80 years. Thus the period of Ehud was not 18 years of subjugation and then 80 years of peace, but a total of just 80 years. When the Judges chronology is worked like that, it fits perfectly into the 480 years between the Exodus and the start of the foundation of Solomon’s Temple (1 Kings 6:1).