Yes, if the expenses are not paid for or he is not reimbursed by his company.
Temporary
assignment vs. indefinite assignment. If
your assignment or job away from your main place of work is temporary, your tax
home doesn’t change. You are considered to be away from home for the whole
period you are away from your main place of work. You can deduct your travel expenses
if they otherwise qualify for deduction. Generally, a temporary assignment in a
single location is one that is realistically expected to last (and does in fact
last) for 1 year or less.
What Travel Expenses Are Deductible?
Once you have determined that
you are traveling away from your tax home, you can determine what travel
expenses are deductible.
You can deduct ordinary and
necessary expenses you have when you travel away from home on business. The
type of expense you can deduct depends on the facts and your circumstances.
Table 1-1 summarizes
travel expenses you may be able to deduct. You may have other deductible travel
expenses that aren’t covered there, depending on the facts and your
circumstances.
Table 1-1 states the
following:
Lodging and meals
Your lodging and meals if your business
trip is overnight or long enough that you need to stop for sleep or rest to
properly perform your duties. Meals include
amounts spent for food, beverages, taxes, and related tips. See Meals for
additional rules and limits.
https://www.irs.gov/publications/p463/ch01.html#en_US_2016_publink10002660
