There are many different things.

1. Hal used multi line comments "/**/", while Satoshi used single line comments "//".
2. Hal added a new line after function return type, while Satoshi put it in the same line.
3. Hal used pointers "*" from C, while Satoshi used references "&" from C++.
4. Hal used Apple preprocessor macros, while Satoshi used Windows preprocessor defines.
5. Hal wrote it in C, while Satoshi used many features from C++ standard library, for example std::pair and std::map.

And so on, and so forth. The code is written in a completely different style, using completely different tools, and even different Operating Systems.

Even if you compare Satoshi's code in C, from the whitepaper, then it is formatted in a completely different way, than Hal's code in C.