B2N2 is correct. Looking up FAR Part 61, I find that not only is it legal to do one's ab initio training in a multi-engined aircraft, but it's also legal for a student pilot to fly a multi solo at night, if he can find an instructor unhinged enough to endorse his certificate authorising him to do it.
Which leads to the next question: did the deceased have an instructor endorsement permitting him to fly the Comanche? If not, then the owner would seem to come back into the regulatory cross hairs.