The Irish-English past-tense form of the verb "to be" is peculiar, a vestige of Gaelic Irish.
In the simple past tense, the Irish say "[am/is/are] after [doing something]
Example: "He's after writing a letter." This is equivalent to "he wrote a letter."
To form the "recent news" past tense, the Irish say "I'm only after [doing something.]" Example: "I'm only after getting here" means "I just got here."
In the "perfect past tense," (he had done something,) the Irish would say "he was after doing something."
It is also common that the past-tense conditional ("would have been") is quite Irish: "one more step and you were f*cked."