QBE was expected to post a net profit of about $535 million in the June half. It says that after its new downgrades, a net profit of $390 million is likely. The difference is $145 million, or just over 11¢ a share: QBE's shares fell $1.32, or about 11 per cent, to $10.57.

Like all companies, QBE trades on a multiple of its earnings, but that explains only about half of the decline. The rest is a confidence hit, taken because the insurer keeps on blind-siding its shareholders.

Neal would only say that the group's dividend policy was unchanged at the briefing he held on Tuesday to explain the latest earnings guidance downgrade.

That policy is, however, for QBE to pay up to 50 per cent of cash earnings in dividends. A June half-year dividend that was expected to be about 18¢ a share could be about 3¢ lower.

The concern, palpable in the questions Neal fielded from insurance industry analysts, is whether even the lower guidance can be relied on.

The insurance group has not delivered a positive earnings surprise for half a decade, and Neal has announced three downgrades since he took over as CEO in August 2012 with a brief to clean up the sprawling global empire his predecessor Frank O'Halloran created.

Including dividends and share price performance, QBE's shares are down 28 per cent over five years, and down 18 per cent since Neal took over. The S&P/ASX 200 index is up 58 per cent over five years on the same measure, and up 38 per cent since Neal became CEO. The financial sector component of the ASX 200 is up 102 per cent over five years, and up 53 per cent since Neal's appointment.

Neal inherited a disorganised collection of businesses from O'Halloran, who bought more than 120 companies in his 14-year stint as CEO. Much of the work he has done to restructure the group and apply common processes was overdue.

This profit downgrade is also driven by what should be a one-off hit: an increase in claims reserves to cover a $170 million negative claims trend in the group's workers' compensation business in Argentina.

A law change about two years ago increased the number and type of workers' compensation cases moving through Argentina's courts. The average size of awards should be falling because less serious cases are being considered, but that has not happened yet, and QBE has decided to use tougher actuarial algorithms.

A related issue is that the Argentinian economy is a mess, again (or, maybe, still). Its currency, the peso, was heavily devalued in January, and has fallen in value by almost 50 per cent in a year. Inflation is running at more than 30 per cent, and a government debt default is on the cards.

Unemployment in Argentina is still only about 7.5 per cent compared with more than 20 per cent in 2001 when the country last defaulted however, and Neal argues that claims reserves have been bolstered to a point where more nasty surprises are unlikely. The business is still making enough money to comfortably beat its cost of capital, and there are no plans to sell it.

Tuesday's news didn't hit QBE's shares as hard as Neal's December announcement of write-downs and charges of $900 million against the group's North American operations. The shares fell by 34 per cent then, to $10.36.

Neil said on Tuesday that businesses in Australia, North America and Europe – that account for about 90 per cent of QBE's premium income – were performing pretty much as expected.

There have been the usual unexpected events, including sustained and heavy flooding in Britain. QBE's North American businesses are also still on probation after last year's losses.

The overall claims experience in the three big markets in the June half-year has been positive to the tune of about $40 million, however, partially offsetting the $170 million negative claims experience in Argentina.

Neal, nevertheless, badly needs clean air. He says his and QBE's history of over-promising and under-delivering is one reason he has heavily provisioned the Argentinian business. The possibility that the average size of claims will decline in future has not been factored in, for example.

Three profit downgrades are two too many, however. Neal was on clean-up duty from the moment he took the top job, and he still appears to have the board's backing. With shares close to their December low again, he and his fellow directors will know that his survival depends on the downgrades stopping.