I am researching a friends family and have come across something I've not seen before

and wonder if anyone can shed some light... I have used fictitious names as owing to the recent nature of events.
Miss Jane Smith was born 1913. In 1934 (Dec qtr) she married Mr Jack Jones. Mr Jones died 1947 (Mar qtr). In 1954 (Mar qtr) Jane Jones married Tom Thomas. A number of children were born to Jane Smith/Jones/Thomas both in and out of wedlock.
In Mar qtr 1948 a child is registered as Ed Jones mother Smith. In the same qtr a child is registered as Ed Thomas mother Smith. The registration district, volume and page number are all identical. This child is the friend I am researching for and family knowledge gave me all the correct surnames involved prior to me finding anything. There is an identical double registration scenario for his sister Mary registered Mar qtr 1950 - same surnames, same volume, same page number.
Both children were brought up using the surname Thomas.
Clearly husband Jones died before either child was conceived and Jane had them out of wedlock as she hadn't married Tom Thomas yet.
If I order the certificates, what info am I likely to find? How was the whole amendment thing handled back then? Or have I likely come across a bizarre coincidence?
Thanks In antic... Vaz
