Increase of gamma readings happened day before the explosion.
I have independent US gamma data available to corroborate. Noticed higher than usual readings one day not long ago, the date escapes me I'll look it up E: MAY7&13. It wasn't high enough above baseline for me to mention, except only because it's already being discussed.
E2: Here is gamma data for May somewhere in America:imgbb link
As per CrazyRussian:
I have independent US gamma data available to corroborate. Noticed higher than usual readings one day not long ago, the date escapes me I'll look it up E: MAY7&13. It wasn't high enough above baseline for me to mention, except only because it's already being discussed.
E2: Here is gamma data for May somewhere in America: imgbb link