Generally, construction work with a value of more than $500 is supposed to be performed by a licensed contractor.
A homeowner can perform any construction work on his own home that he wants, without having a license. A homeowner can hire anyone he wants to perform construction work on his home, whether that person has a license or not. A homeowner that does that is putting himself at some risk, such as having someone get injured on his property, or having shoddy work performed, but that is the owner's problem.
The person performing work that requires a license is violating the law, and could be subject to prosecution, and would not be able to force the owner to pay him, if the owner chooses not to pay, so there is some risk to the non-licensed person also.
For your specific situation, the owner does not need a license and can hire his property manager to perform construction work. The property manager does have some risk in performing unlicensed construction work. If you get prosecuted for unlicensed contracting that could result in you losing your DRE license as well.