There had to be a McVeigh - Doyle marriage for John McVeigh to have a grandson named James Doyle.
There are records on the same volume and page of the indexes for 1870 marriages of a Jane M'Veigh [note the apostrophe when searching for the record online] and a John Doyle. If they are on the same page, they married someone else on that page.
Send for one of the records to see the father's name and townland, which should clear things up for certain.
Here are the two references to the indexed marriage records:
Ireland, Civil Registration Indexes, 1845-1958
Volume Number: 1
Page Number: 715
for Jane M'Veigh
"Ireland, Civil Registration Indexes, 1845-1958," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/FYSK-HJ9 : accessed 25 Nov 2013), Jane M'Veigh, 1870; citing vol. 1, p. 715, General Registry, Custom House, Dublin, Ireland; FHL microfilm 101251.
for John Doyle
"Ireland, Civil Registration Indexes, 1845-1958," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/FYSP-9ZX : accessed 25 Nov 2013), John Doyle, 1870; citing vol. 1, p. 715, General Registry, Custom House, Dublin, Ireland; FHL microfilm 101251.