Google your urban dictionary to find out what Lean is. The third ingredient is Robitussin. Martin discussed it on his Facebook page!
Apparently according to his autopsy toxicology report, Martin's liver was already showing the negative effects of his consumption of the DXM in the Robitussin.
DXM can cause extreme agitation and paranoia.
On Martin's Facebook account, he is actually asking someone where he can get some codeine! He says the codeine gives a bigger kick than does the DXM.
The euphoric effects of DXM becomes more muted the more it is used, so Martin's desire for codeine tells us he'd been doing it for a while. There is evidence he was using it since sometime in 2011.
Now we know why Martin acted like an aggitated paranoid idiot. Z told the dispatcher that Martin appeared to be on drugs very early in the call to the police. Martin was correct.
Here is a link to the story including page captures of Martin's Facebook discussion of DXM and codeine.
Pray for me.