Although expert testimony can touch on ultimate issues of fact, see N.C. Gen. Stat. § 8C-1, Rule 704, experts cannot testify on ultimate issues of law:

[A]n expert may not testify that a particular legal conclusion or standard has or has not been met, at least where the standard is a legal term of art which carries a specific meaning not readily apparent to the witness.

State v. White, 340 N.C. 264, 294, 457 S.E.2d 841, 859 (1995). The term “proximate cause” is a legal term of art, and thus is an ultimate issue of law.  See State v. Ledford, 315 N.C. 599, 340 S.E.2d 309 (1986) (holding that it was error to allow an expert to testify that the injuries suffered by the victim were the “proximate cause” of her death); State v. Rose, 323 N.C. 455, 459, 373 S.E.2d 426, 429 (1988) (medical expert could not testify that a defendant did or did not "premeditate and deliberate", testimony embraced precise legal terms, definitions of which are not readily apparent to medical experts); State v. Weeks, 322 N.C. 152, 165-67, 367 S.E.2d 895, 903-04 (1988)(trial court did not err by refusing to admit testimony of medical experts that the defendant did not act in a "cool state of blood," testimony embraced precise legal terms, definitions of which are not readily apparent to medical experts);  State v. O'Hanlan, 153 N.C. App. 546, 557, 570 S.E.2d 751, 758 (2002) (doctor's opinion that the victim was kidnapped and raped was improper); State v. Galloway, 304 N.C. 485, 489, 284 S.E.2d 509, 512 (1981) (medical expert may not testify that the defendant raped the prosecuting witness).