

We had that in our DOS C code base. We didn’t have a debugger so we had a function that output debug messages to console if the debug flag was set.
There were more than a few instances where a crash would stop happening if we added debug messages.
We put it down to the linker rearranging modules to fit in memory as our exe was more than a megabyte in size.
Deterministic means for the same input you always get the same output.
For AI it would be if you ask it a question multiple times using exactly the same words you would get the same answer.