If it makes even a 5% difference in the likelihood of acquittal, I'd think a lawyer would be well worth the money. And in a case like this, I think it very easily could make a difference.
Lawyers can be expensive. If BMS has money to burn, then he might as well get a lawyer. But otherwise, I think he ought to establish that the State is serious about pursuing this (which I rather doubt), before spending money on a lawyer.