The T-1000 was unable to dodge Sheyan's kick because he had launched his feet really quickly, but as a result, the damage done was very low.
Fortunately, the fundamental purpose of this kick was not to deal damage, but to make the T-1000 lose its balance. This was the plan Sheyan came up with after the painful lesson he learned from his previous encounter with the T-1000. He would not get entangled with the Terminator in close quarters. Every time after he got in a strike, he would retreat and start over again!
In addition, he must avoid focusing his attack on the hands and feet of the T-1000 because these parts were completely unaffected by normal human structure and could change unpredictably. To focus his attack on these parts was to ask for a beating.