Under what circumstances must a jury be instructed on every theory that is supported by substantial evidence?

"A trial court must instruct the jury on every theory that is supported by substantial evidence, that is, evidence that would allow a reasonable jury to make a determination in accordance with the theory presented under the proper standard of proof. [Citation.]" (People v. Cole (2004) 33 Cal.4th 1158, 1206 (Cole).) However, "Trial courts are duty-bound to avoid instructions which are not justified by the facts of the case, since they have a natural tendency to overburden and confuse the jury. [Citations.]"

Page 17