Your hacker may be fulfilling another job's worth of responsibilities in his spare time around the office. My hacker doesn't speak English. Your hacker is a techie. If you have trouble understanding that reference, ask your hacker if she has a copy, or would be willing to explain her terms. Most hackers are willing to explain terms.
Hackers love word games.
Your hacker hasn't figured out how hard the problem is yet. Unlike most workers, hackers will try very hard to refuse to give an estimate until they know for sure that they understand the problem. This may include solving it. Most hackers are good engineers. Still, it's an estimate, and you get what you ask for.