Yeah, this looks a bit more like Solanum vescum to me, and it commonly comes up in abundance after fire. It tends to have minimal or no indentation between the corolla lobes (petals) as here, while S. aviculare has alternating dips and points around the corolla edge, at least in all the photos I've taken so far of the two species, though this is not mentioned in the books.
Also, S. vescum is branched from the base, while S. aviculare tends to have a single trunk and branches higher up. Maybe you could check these features and put up a better front-on flower shot.