When Jake was talking about giving Amelia 40mg of oxycodone it could've been two tablets of oxycodone immediate release 20mg, however when Addison and Sheldon returned with a single tablet it was obviously supposed to be an Oxycontin tablet because oxycodone immediate release do not come in the 40mg strength. The error is that Oxycontin has been reformulated so that when crushed and snorted, it no longer gives a "high" to drug users.