Cops Destroyed Evidence

My son goes to trial tomorrow in Massachusetts on an old drug charge, and his Public Defender found out today the the drugs in question, the evidence, have been destroyed. Is this good news for my son, who allegedly sold a gram of coc to an undercover female officer in the bathroom of a nightclub!
Is there any precedent for dismissal?

Q: Is this good news for my son, who allegedly sold a gram of coc to an undercover female officer in the bathroom of a nightclub!
A: No, they have all the lab reports showing what it was.

I agree with SeniorJudge on the issue of the lab reports, but here is a tricky little "talking point".

The defense has the right to examine and test the evidence to be used against the defendant. (Oddly enough, in the technical sense, this evidence is known as the corpus delicti.)

What evidence? Where is the evidence to examine and test?

The "State" has a duty to safekeep, track, log, and verify the path and whereabouts of any and all evidence in its possession and control.

(In theory, it could be argued that a prosecutor's 14-year old child could have created a lab report.)