Indeed he is speedhacking, and I'll brief how speedhack works.
K, when you see a clean player, the speed-o meter and the tachometer needles will move smoothly while an engine modification or hp increase(speed hack does that) the needles will act wierd, like the the player is lagging but he isn't its just a diferent power value the game detected and it'll act wierd o.0
So when u see a player with 90ms of ping and the needles are behaving wierd, its clearly speedhack, even 1 hp will make the needles act wierd (crash mod and other stuff doesn't affect/delay with the needles movement)
P.S: higher ping just delays the car position the speed-o meter and tachometer needles will still move smoothly
Cheers.
(
Maybe I'm just saying something obvious but I'll say it anyway lil)