Yes, that is one of the options. They can also represent themselves, or hire a lawyer. What else could they also do? Run away to another country maybe?
To clarify, in some jurisdictions in the US, businesses cannot represent themselves. Which is a travesty for companies like this guy, who doesn't even have that as an option. I don't actually know about patent law, I just have had an experience with a frivolous lawsuit for a low-ish dollar amount that it would cost more to defend than lose. Because we couldn't represent ourselves, we just had to let it go to default judgement.
Actually, most states have restrictions against non-attorneys representing a business in court. (See for example for CA Merco Construction Engineers v. Municipal Court.)
Otherwise however a business can represent itself in court, so long as its representative is a practicing attorney. Many states (but not all) won't require the attorney to be licensed in the state of litigation so long as they are licensed elsewhere.
Also, all states will allow a business to represent itself in small claims courts, where attorneys are not allowed unless they happen to be an employee of the business.