Yes, both are definitely snapped off and not impressed marks, Trevor.
The small green/purple vase has a larger diameter pontil scar than the heavier bowl.
Aside of an ebay listing some time ago, your blog is the only other example I can recall showing this type of pontil scar. You have suspected Rob Knottenbelt work, more so due to decoration and style though. Perhaps someone working with him at the time, and maybe used to distinguish who produced what piece in those trailed silver chloride examples? http://australianglass.blogspot.com.au/2015/09/robert-knottenbelts-early-production.html
I do recall discussion on GMB mentioning pontil preparation along these lines though. Can't find it using site search.
Easy enough to do I suppose, impress cross mark into a pointed form pontil gather prior to attachment, but I can't see a lot of advantage in doing this type of pontil attachment other than for large heavy pieces, perhaps providing additional support during forming over larger area.
I'd imagine riskier snap off procedure though, having it crack across all points evenly when shock applied to the rod on one side. Perhaps why the larger vase required grinding off a residual bur at two of the points.
Any idea which school of training used this pontil prep technique, folks?