Is there a risk of explosion if a butane lighter is used to ignite an improvised explosive device?

Prosecution witnesses had conflicting opinions regarding the functionality of the IED, but the device was not designed to be self-detonating. There was no timer switch or means of remote activation. According to the evidence, "the only way to attempt to set off that device would have been lighting the fuse." Defendant's briefing erroneously refers to the presence of a "butane lighter" inside the DVD box, but the item was repeatedly described as a butane "container," "canister," or "can." Regardless, a hypothetical concern about the potential risk of explosion during transport does not make it equally likely defendant assembled the IED in the parking lot instead of driving it there from another location. The jury could have accepted the testimony regarding the lack of functionality, rejected the conflicting opinion testimony, and inferred defendant's knowledge there was little or no risk of an explosion during transport. (See People v. Langley (1974) 41 Cal.App.3d 339, 348 ["[T]he trier of fact may reject a part of the testimony of a witness while believing other portions of his testimony"].)