So you dont have any contact to this person so you cant just simply ask?
In that case I guess there is no possibility to ever know, I mean it could be derived from any TEK and then any post treatment could be made, so the final morphology was achieved.
Generally STB TEKs are told to yield less pure Spice and FASA / A/B TEKs are told to produce higher purity / solid crystals.
But maybe she/he did a very clean workup on a very high quality ( = less oil) bark and therefore only a regular STB method was used, one will neber know :/
Using recrystalizaton after a *dirty STB* would also create a product that is similar to yours.
If you are now curious about that nice purity and the solid product that you were given and you want to move over from sticky goo to a product like this, then you should simply do a recrystalization on your goo or also try a A/B. Last possibility of course would be using MHRB, but you already told that you both had the same initial source, so this may not be the reason. Still switching over to MHRB would most likely *improve* the rheological properties of your product.