I didn't see in the article any reference to the economy's performance prior to the tax hike (tax hike occurred April 1st, and Japanese consumption tax is levied on everything - houses, groceries, medical services, etc.). I know that many households scurried to make "big" purchases prior to April 1st. Cars, electronics, new homes, vacations, what not. So, naturally one would expect a decline in consumerism after April 1st.
An interesting side note - prior to the tax hike, all items for sale had to be advertised by law with the consumption tax (then 5%) included. So, if a bakery was selling bread for ¥99 a piece, that's the price you'd pay at the register. After April 1st, the law changed so that prices can now be advertised without the tax included. So now at this particular bakery I mention, bread costs ¥111 a piece. AND when you pay, they tack on 8% at the register. So now my ¥99 bread is going to cost ¥120. That's quite a markup for a tax that only increased 3%. Needless to say, I eat mostly rice.