Scotmum
I do agree with that statement. QUB digitised GRONI's records 2009-11 and they seem to rely on them entirely and not make any recourse to the old paper book indicies.
The English and Welsh GRO is similarly restrictive on their system requiring a surname but the indices are online till 2005 on Ancestry, FindMyPast, FreeBMD etc. The Scottish search system is better but only gives you year and some mother's maiden surnames (those are the the most prone to transcription errors as only written once on a birth entry). No old Vol/page online indices are available for NI post 1921.
What was digitised by GRONI appears to be the
original Birth, Death and Marriage Ledgers. They have no loose leaf quarterly copies prior to 1922 just the original bound books which were kept at Local then District level when full (they should have quarterly copies 1922 until they became digital).
There are differences, especially in marriages as copied by the ministers - not always an exact replica of spelling, especially in the early years reading a book in poor lighting and writing on loose sheets & who needed to go to Specsavers.
I've been comparing geneology.ie marriage images with GRONI using
http://www.irelandgen.com/tools/gro_img_nav.php and there are some entire marriage books missing on GRONI's system the worst being Linenhall Street Presby, Belfast, marriage books 1-5 1845 to 1865 (at least) GRONI have no record of in their index. St John's Tyrella CoI, no entries found on GRONI index 1846, 48, 72, 75, 1910, 1913, 1915. But also the 1st Book of Newtownards Registrar's Office and a few other small meeting houses where marriages occurred so infrequently is hard to find more than the one or two entrys on the page to cross-check.
Books did get stolen
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1856/09512/5447813.pdf but they still had the other one to copy again in the church and were issued another pair of two. Churches burnt down and were blitzed - that was the point of the quarterly copies, always storage in 2 places apart from the last few months.
So did they miss scanning some books or are the books missing, I intend asking them.Along why why a QC was not performed to check for impossible dates - there are entries Jan-Mar 1845 before Civil Marriage Reg started. Of the 30 odd I have come across only 2 have been a period error of Jan 1845 instead of Jun 1845 (made by the Downpatrick Registrar who misunderstood proceedures & copied all the Church marriages into his book 1845 & 1846, so there are 2 copies in Dublin & 2 in GRONI of them, one written by the Rector/Curate and the other by the Registrar - the church entry says Jun badly but is after May and before Aug). All the rest are errors and I purposefully have not reported some yet.
M/1862/B1/418/19/35 Robert McDonald & Rankin indexed 18th February 1845 Belfast actually 18 Feb 1862.
M/1907/E1/1766/4/56 Mary Magill & Moorhead indexed 29th March 1845 Lisburn actually 28 March 1907.
Some errors are both ref year and marriage year and they don't change the ref. when correct the date so there is a difference then.
M/1919/Y1/2198/1/12 Oliver McFarland & Ballantine 24th August 1919 Omagh actually 24 Aug 1911 - advised & corrected from 1919 to 1911 without any change to ref code.
Also R.C. marriages registered by return of signed paperwork following ceremony, well some grooms were tardy and didn't till weeks or months or a few years later (or not at all hence only in the R.C. NLI images). The Ref year is the registration year for those, so may correctly differ from the marriage date. Same for by Special Licence married 28th Dec 1900 & registered 3 Jan 1901 will have M/1901/
https://www.nisra.gov.uk/sites/nisra.gov.uk/files/publications/1934.pdfhttps://www.qub.ac.uk/research-centres/CentreforDataDigitisationandAnalysis/Research/ProjectsCompleted/2012-2013/#d.en.1005079I don't intend doing any sort of cross-check of births & deaths but like you have burials and newspaper notices with no registration, however, a burial could legally proceed before a registration until 1926 (England & Wales, perhaps later N.I.).
A distant relative's death was registered Monaghan 21 Oct 1930 11˝ months after his death 6 Nov 1929 as reported in Newspapers and probate calendar but recorded as death 6 Nov 1930 on the quarterly copy image online so according to GRO Dublin his death was registered before he died.
In your case seems to have been a spelling error and for Grohls-wife an omission of surname.