Still using my 40 equips and gear.. But here's proof that I managed to do it.
lets see in the order I see on this screen you made a total of 8 attacks:
1: Twin fang shot: 17231hp
2: TFS procs second attack for 21539hp (side note: unless mob has over 20k hp this might have been a second attack)
3: Swallows guide Shot: 22882hp
4: Basilisk Shot: 15719hp
5: normal attack: 40900hp
6: Shadow arrow: 6361hp
7: Swallows guide shot: 50212hp
8: SGS (possibly procced a second attack or was used again): 50213hp
therefore 1 shot did not deal 100,000 but 50,212 or 50,213 depending on which shot you look at. therefore your max damage you did in only 1 shot was 50,213.