I don't see how it is different. A "higher level of abstraction" means progressively higher-level versions of source code. Binary->machine/assembly code->C++ code for example. Each step involves reverse engineering. Simply disassembling/decompiling a binary is not really sufficient to be considered "reverse engineered". Someone needs to analyze the output of these tools to create reverse-engineered output which is ready to be modified/extended/investigated.

I disagree. The author implies several times that the main issue, and the reason for the ban on reverse engineering in the agreement, is protection of intellectual property (source code). People may do other types of vulnerability testing, but the piece that Oracle is concerned about is trying to discover their source code (for example, by using static analysis tools...which analyze some version of source code).