Decision tree and information-theoretic lower bound
No.  The outcome is the median, not the sorted list. Thus, there are only 3 possible outcomes, not 3! outcomes.  The information-theoretic lower bound says that if there are N possible outcomes, then it takes at least $\lceil \lg N \rceil$ comparisons.  (Proof: given $k$ comparisons, you can only produce $2^k$ different outcomes.)  Here $N=3$.