A situation where we observe declines in the prices of some products does not qualify as deflation in this sense. It is nearly always the case that prices for some things are falling, while prices for other things are rising.
Were we to look at the 100-odd expenditure classes in the Australian consumer price index, we would find that about 30 of them record a decline in any particular quarter. This has been a feature of the low inflation era since 1990.