When to use definite and indefinite articles

“On a day that Health Cabinet Secretary Mutahi Kagwe admitted the virus was now being spread through community transmission, the government was toying with the idea of either locking down the entire country or the four counties of Nairobi, Mombasa, Kilifi, Kwale that have been declared hot-spots”.

This quote from a local daily caught the attention of someone at The Media Observer (TMO) who, mockingly, wrote; “You can imagine government officials gathered somewhere enjoying a cold beer, biting chicken wings and breaking out into uproarious laughter as they toyed with the idea of locking down the country. To “toy with” means to consider (an idea) casually”.