The sudden increase in skill is due to the weapons that i used in the game.
I take example on the game: "flooded zone on the 07/20/20 at 09:42PM", apparently a very suspcious game where i did "62 kills" and "28 deaths" with my best weapon in the game: "aek-971". Sometimes in the game, i didn't play with aek but with the CS-LR4 and the M200 Cheytac so we can't say that my accuracy is suspcious.
Moreover, if we look at the game duration, we can see that the "round tooks 2269 seconds" to finish compared to my other games, so i had time to perform a lot of kills in this game.
I had the instant replay with shadowplay and i recorded some parts where i was playing with aek and CS-LR4 if needed (i'll try to upload it as fast as possible even if i got a bad connection).
Source: http://bf4cheatreport.com/?pid=1878322484&uid=&cnt=200&selectreports=1285602654710153408,1285319780008786240,1217149164906381376,1263864440205330496#a