We don't actually know if the weed was hers or his. I bet it was his, but we don't know it as fact. I tend to think it was his because of the grinder which ordinarily might not be carried around. (I assume). On the other hand, if it were his and part of his property, then you'd think he also had some way to smoke it in his apartment such as paper, bong, pipe, etc. If he had a grinder, then I'd also think that he were growing it, but that is not in the police report either. I have to assume there was such or that the police report just doesn't contain that info, but I cannot be sure. I don't think this is as straightforward as some would like to think with Occam's Razor.
Another possibility here is that Guyger had all sorts of drugs paraphernalia in her apartment, but police gave her a full three days until arresting her and so she may have destroyed all that missing evidence, such as growing plants, bongs, rolling paper, a pipe that she had as opposed to Botham Jean. Since police did not immediately hold her in custody as they would a normal citizen we're not able to analytically test this alternate scenario.
Your scenario, that she planted the weed would require her to have 10g of weed and a grinder on her when coming home from the job.
I don't think it does. Any cop could have planted this at any time in order to support Guyger. Or Guyger could have stolen the weed from the office. Maybe there is a network that distributes pot to the cops within the police office since weed is fairly harmless and they possess the weed from confiscations. Or maybe she picked it up from a supplier on the way home.
Also, it's a pretty useless frame-up.
Well, suppose it were his. Then, announcing it may lead to a little extra support for Guyger which seems to be a goal of the police right now, not their normal procedure as applied to regular citizens...that's not a frame-up but it's generally what people are talking about.
Anyway, that is one case where it is not the kind of frame up you are asserting people are saying. Another is that Guyger had weed on her. Then, she realized police would be coming, so she dumped it in one of Botham's drawers. Not a pre-meditated frame-up, just incidental....though her smoking weed could be related to the shooting.
While I think the weed and grinder were likely his, I reserve the right to revise my opinion, if Guyger's toxicology report is ever released and that is not an obvious switch of results with another cop such that it shows she has smoked weed recently, in which case I would then think the weed was likely hers and played some role.