You could do the same on compiled C by attaching gdb to the process and changing the timeout value so this has not much to do with "scripting". Just saying.

True but this was only about values. Changing values is not the most you can do with dynamic languages at runtime. In Python it is possible to create a completely new method implementation at runtime.

Not to say that dynamically changing code at runtime is totally impossible in C - buffer overflow attacks do exactly that.

Depends on how you define a "scripting" language. If you mean an interpreted language, then it's not true; you can do hot code swapping on native code. Erlang's HiPE does this.