OK I had a brief look at the link. I'm not familiar with the author but it clearly is based on a belief that karmic influences can be seen in a chart.
Now I don't particularly dispute that, but one thing is fairly clear and that is that there is no consensus about how karmic influences manifest in a chart. The trouble is that obviously there is no way of an experiential test, which there is for most other Astrological contentions.
The second observation is that the article, very sensibly, says that the connections need to be read in the context of the chart as a whole.
Now, in a non-karmic synastry context, I would not place much if any emphasis on a Saturn Neptune conjunction in Sagittarius in the Ninth. Especially as the degree of separation is wide. I'd really only pay attention to such conjunction if there was less than 2 degrees separation and better still less than one degree. The only thing that can be said for it is that the aspect in an applying one.
Now without any information on the rest of your chart, I would not say anything hard and fast. Saturn in your ninth, could indicate a desire to have a structured approach to higher education, religion, the law - if you like your conscious adult reactions to society's norms. As Saturn is not particularly strong in your chart, it might indicate some difficulties in adopting such a structured approach. It perhaps doesn't work as well as you'd like.
Now if his Neptune was within a degree of your Saturn, I'd hazard a guess that he (through his behaviour and interaction with you) 'clouds' your attempt to impose your structured approach,, or at least adds some fogginess to your approach. However, given the actual separation, I'd tend to discount that unless it was corroborating evidence of something that was strongly indicated elsewhere.
Now the extend to which my approximation of your Saturn, is accurate will depend very much on the rest of your chart. It may be something that is more than compensated by other things. At worst, it's nothing particularly bad and means that you have to work a little harder to impose some sort of structure on ninth house issues.
I've not dealt with the Karmic dimension but that's because it's not an area that I claim any competence in. I think it depends very much on your belief structure and whether it fits in to that. As I said above there's no real way of demonstrating it either way.
Also if you're doing some reflection, it may be more useful to reflect on what you know you went through because it's more likely that a conventional examination would provide some indicators of why you and your ex split. Only if you can't find any at all is it worth pursuing a karmic connection.