They only pay £500 if you're already on low income. Is there any basis to your claim that suddenly a lot more people started getting infected? It's my recollection that cases were already rising fast when this was announced.
I know 4 people who deliberately got infected to claim the £500. Three have been paid (one is stuck in paperwork hell). I know of two others who tried to, but despite their efforts couldn't get the test to come back positive.