This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
No it is the recommended behaviour according to the JDBC specification ie documented rather than actual behaviour.
People have gotten it wrong before, it is safer to lose the ResultSet explicitly (in my opinion)