They have bigger problems than their online services. I think the real problem of both Coles, Woolies and possibly Aldi is their supply logistics planning and implementation was not designed for this situation. It has been ten days and some essential products are still missing from the stores.
Blaming it on"Panic Buying" is a problematic and doesn't make because shoppers don't have anything available to buy.
"Panic Buying" does become a convenient excuse for politicians and the supermarket corporate media plus it makes nice media headlines.