Okay, logs time.
These are logs with grenades from the round you were banned:
Line 132: Line 7562: [2020-09-11 22:06:09.493] GAME: Maslav/(John Johnson) primed a chemical grenade at Courtroom (0, 0, 0) containing: (large beaker 1 : Potassium, 100); (large beaker 2 : Water, 100);. (Courtroom (114, 149, 2))
Line 147: Line 8355: [2020-09-11 22:10:37.435] GAME: Maslav/(John Johnson) primed a chemical grenade at Research Division (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Research Division (111, 108, 2))
Line 149: Line 8359: [2020-09-11 22:10:37.443] GAME: Maslav/(John Johnson) primed a chemical grenade at Research Division (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Research Division (111, 108, 2))
One in court, which is, I suppose, one meant for lawyer and clown and two in RnD for some reason.
Now, I dived a little more and found these. Same day, just few rounds back:
Line 105: Line 9807: [2020-09-11 18:28:07.784] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 136, 2))
Line 107: Line 9809: [2020-09-11 18:28:07.786] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 136, 2))
Line 109: Line 9811: [2020-09-11 18:28:07.788] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 136, 2))
Line 111: Line 9813: [2020-09-11 18:28:07.792] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 136, 2))
Line 113: Line 9816: [2020-09-11 18:28:09.048] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 141, 2))
Line 115: Line 9818: [2020-09-11 18:28:09.051] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 141, 2))
Line 117: Line 9820: [2020-09-11 18:28:09.053] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 141, 2))
Line 119: Line 9822: [2020-09-11 18:28:09.056] GAME: Maslav/(John Johnson) primed a unsecured chemical grenade at Bar (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (126, 141, 2))
Line 122: Line 10544: [2020-09-11 18:32:40.303] GAME: Maslav/(John Johnson) primed a chemical grenade at Honked 'n' Loaded (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (127, 135, 2))
Line 124: Line 10548: [2020-09-11 18:32:40.308] GAME: Maslav/(John Johnson) primed a chemical grenade at Honked 'n' Loaded (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (127, 135, 2))
Line 126: Line 10552: [2020-09-11 18:32:40.314] GAME: Maslav/(John Johnson) primed a chemical grenade at Honked 'n' Loaded (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (127, 135, 2))
Line 128: Line 10556: [2020-09-11 18:32:40.319] GAME: Maslav/(John Johnson) primed a chemical grenade at Honked 'n' Loaded (0, 0, 0) containing: (large beaker 1 : Water, 100); (large beaker 2 : Potassium, 100);. (Central Primary Hallway (127, 135, 2))
A LOT of bombing for a non antag Station Engineer.
So in conclusion, you bombed 3 times as non antag on the round you were banned and bombed a lot of times few rounds back, and I fail to see a reason why.