X-class flares from our sun are 10E32 or so ergs. The black hole flares were roughly 10E35 ergs, about a thousand times more energetic but they are about a billion times farther away than our sun. Apply N^2 law and . . .

The amount of radiation you received from the Sagittarius flares is almost indescribably tiny. Many, many orders of magnitude less than the cosmic ray background radiation that we already live with. If you didn't have a sensor pointed right at the BH, you wouldn't be able to distinguish it from the noise.