My co-worker does the same thing. Thinks instead of opening the debugger. In fact, he never uses a debugger even though he's a hardcore low-level C/C++ guy. Another important thing is to have good logs. Don't log too much, but log the most pertinent info. Next he just looks at the code. If it's really tough, he adds a print statement or two. I've never seen him do more in 3 years of working with him.