I think the votes for the UK entry from the Irish viewers might actually not have been that friendly. The only reason I can imagine voting for it would have been as an act ridicule.

"Malta was not, and is not a British possession" It was a British Crown Colony from 1814 until it became independent in 1964, and a republic in 1974. (And of course several of Cyril Tawney' songs are set in Malta.)