For a few days, delegates from the other side of the Indian Ocean got to walk and talk freely without being surrounded by poverty or concerned for their personal safety, in a country free of the historic baggage of Africa’s occupying colonial power.

Australian investors, on the other hand, got a close look at what Africa has to offer and a chance to ask questions of African business and government leaders – and that’s when the case for investing in Africa starts to weaken.

It is likely to weaken further next week when Africa discovers that a rival continent is making a return as an attractive destination for exploration and mine-development dollars – Australia.

In what looks to be a pincer squeeze on an entire continent, Australia is heading for the return of a pro-mining administration just as risk rises back to the top in Africa.

The Australian leg of the squeeze will become clearer after Saturday’s election. The African leg could be clearly seen at the ADU conference.

To test his theory, at least at an investor level, Dryblower applied three measures, starting with an assessment of the major speakers, then gauging the level of interest after opening day and finally, by applying a share-price test.

The first step in this three-pronged process was to listen to the two big guns of the conference, and assess whether their messages had substance.

One of the guns was political, South African Mines Minister Susan Shabangu. The other was commercial, chief executive of Gold Fields Nick Holland.

Both Shabangu and Holland had a lot to say, but also managed to leave a lot unsaid.

In a way, it reminded Dryblower of a famous court case starring a man about to become a minister in the first Abbott Government, Malcolm Turnbull.

Back in 1986, during what was dubbed the Spycatcher trial, Turnbull, then a practising barrister, accused Britain’s top civil servant of being “economical with the truth”

It was a marvellous moment and it helped make Turnbull’s reputation, because not many people had ever dared to tell the UK Cabinet secretary, Sir Robert Armstrong, that he was not revealing all that he knew about an alleged spy at the centre of British intelligence.

Shabangu and Holland were being equally cautious in describing the politics and investment appeal of Africa’s biggest economy, which was once home to the world’s biggest mining industry.

The minister skipped lightly over the industrial relations, corruption and red-tape chaos that is making South Africa an investment no-go zone, a situation easily measured by the collapse in value of the country’s currency over the past month.

Low metal prices are not helping South Africa, but neither is greedy government driven by a deep-seated socialist ideology and a failure to see that the rise of a black elite will cause the same crisis that developed when a white elite grew rich on cheap labour.

Holland was equally economical with his words, arguing that Gold Fields remained a South African company despite just 11% of future gold production coming from its homeland after the latest deal to buy Australian assets was complete.

He is probably correct in saying head office will remain in Johannesburg but the money, which is what really makes a company, will be elsewhere.

No amount of spin can take away the fact that Holland has voted with the capital of Gold Fields and is sending it on the same trip so many of his countrymen have made – out of Africa.

The second test was to judge the mood of delegates after the opening day excitement and it’s fair to say that many were underwhelmed by the response of potential Australian investors to their attempts to market Africa as an investment destination.

What the delegates from African discovered is that the risk/reward ratio of Africa has become more negative as mineral prices have receded and political nationalism has risen.

The third test was to measure the Australian stock market reaction to companies that spruiked their African assets, an assessment that was less than inspiring.

Of the 30 ASX-listed companies presenting at ADU, most failed to react positively on the market – with 23 (77%) either incurring a modest share price fall during the three days of the conference, or no movement at all, while seven (23%) managed a small rise during the conference.

Not an accurate test. The stock market reaction in a week when African mining was in the headlines can be taken as a measure of fading interest by Australian investors as the appeal of their own country heads down the road to mining recovery.