Rarely can the phrase being thrown in at the deep end to describe the challenges of a new job be more apt than in the case of Alex Fergusson. The Conservative MSP for Galloway and Upper Nithsdale was yesterday elected Presiding Officer of the Scottish Parliament. He has been an MSP since the parliament's inception, first as a list, then as a constituency representative. He increased significantly his majority in this month's elections, which suggests he has done a good job for the people of that part of south-west Scotland. How he shapes up as Presiding Officer will be measured differently.

It is not primarily on representing the interests of his constituents that he will be judged. The true test will be steering Holyrood through uncharted waters, where hidden dangers lurk that could blow the devolution project off course, with potentially momentous constitutional consequences. It is likely that the parliament will have the first minority government in its short history when the fallout from the election settles, with the SNP forming the administration, supported by the two Scottish Green MSPs.

What this means for orderly government is unclear. There will be votes on a predominantly SNP agenda on a policy-by-policy basis. This could be a recipe for instability if the government were voted down on a succession of proposals. The scenario is a consequence of the electorate casting votes in a part-PR democracy. It is already known that this can produce unintended, not to say embarrassing, consequences, with perhaps 100,000-plus voters being disenfranchised because the Holy-rood ballot form, significantly altered compared with past elections, seemed to cause widespread confusion. Holding the local authority ballot at the same time probably did not help. A failure to deliver postal ballots in time added to the ranks of the disgruntled disenfranchised.

All of these factors will be investigated by Ron Gould, an expert on elections who was yesterday appointed by the Electoral Commission (EC) to review what went wrong. This is a step in the right direction, as the election failures demanded much more than the routine EC review; an independent inquiry with powers to summon politicans, officials and others to explain and justify their roles, in fact. Yesterday's announcement unfortunately falls short of expectations. Part of Mr Gould's remit is to examine the role of the EC. That must be a critical element in the investigation, as the EC had a role in the process leading to a voting scenario that caused so many problems.

How independent can Mr Gould be when he is appointed by the EC? To whom will he report? Robust inquiries that produce blunt conclusions tend to be divorced from the organisations under investigation. This review risks being viewed as tainted, from day one, because of the model chosen.

Mr Gould recognised yesterday that democracy depends on public confidence in elections; in parliaments, too, he might have added. Mr Fergusson faces a daunting challenge to deliver on that score, given the scramble for votes and deal-doing that might emerge in the weeks ahead and, potentially, further turn the public off politics. The water is deep. Mr Fergusson, with no experience as a Deputy Presiding Officer, jumps in as a novice. He faces a tougher task than either predecessor. He must learn quickly.