1813 plague and Qormi

During the course of research for a book I'm writing, I happened to read this paragraph which I am quoting verbatim from Giovanni Bonello's Histories of Malta Volume Four - Convictions and Conjectures, section entitled "Mementoes of the 1813 Plague", pp. 141-2, published by Fondazzjoni Patrimonju Malti in 2003:

"Qormi's two rival parishes, St George and St Sebastian, also saw to lasting memorials of the plague. An elaborate silver lamp (lampier), hanging in the choir with a commemorative inscription, harks back to those tragic days. St Sebastian's raised a statue of its patron hewn in stone, placed prominently and publicly as an act of thanks for the abatement of the plague. Statues, similarly in stone, representing Our Lady of the Rosary, were also erected on the same occasion in Qormi and in Hal Dwin."

It may interest the writer of this paragraph to note that, in 1813, there were no rival parishes at Qormi for the simple reason that the village was just one parish. The smallish, but architecturally-interesting, church of St Sebastian, which is in front of the statue he mentioned (erected in 1815 and blessed by the parish priest of St George's parish) was constructed between 1880 and 1890 (when it came into use) and was erected to parochial status on January 5, 1936, quite a number of years after 1813.

The writer was again off the mark when he referred to the Qormi street statue of Our Lady of the Rosary which has no connection whatsoever with the 1813 plague. This statue was erected in 1888 by Luigi Frendo in thanksgiving for his family being spared from the cholera epidemic of 1887.

Since many people I know, not necessarily Qormi-born, take this as common knowledge, I wonder where the writer got his information from and whether it was the fruit of conviction or conjecture.