Perhaps John chose not to record the fact that Judas identified Jesus by kissing Him to strengthen the force of Jesus" question. He mentioned Judas" presence nonetheless since He was a primary figure in Jesus" arrest. John stressed Jesus" complete control of the situation. [source][source][source]
Jesus responded with the clause, "It is I" (Gr. ego eimi). As we have noted elsewhere, this was a claim to deity when Jesus uttered it in certain situations (e.g, John 8:24; John 8:28; John 8:58). However it was also a normal way to answer the soldiers here (cf. John 9:9). Some interpreters have concluded that John"s description of the soldiers" response to Jesus" identification of Himself indicates that they viewed His words as a claim to being God (cf. Psalm 27:2). However on other occasions when Jesus" hearers understood that He was claiming to be God they tried to stone Him. Here they momentarily fell backward, stood up again, and proceeded to arrest Him. Perhaps John was hinting to his readers that the soldiers responded better than they knew by falling backwards. However, it seems unlikely that they took Jesus" words to be a claim to deity in this context. They probably fell back because they could not believe that the man they had come out expecting to have to hunt for was virtually surrendering to them. Rather than having to hunt down a fleeing peasant they found a commanding figure who confronted them boldly. [1][source]
"It may well be that in John 18:5-6 John recorded an incident in which the opponents of Jesus recoiled from surprise or abhorrence of what they perceived to be blasphemy. But for the reader of the gospel, who already knows who Jesus is and that His claim to identification with God is true, the reaction of the enemies is highly ironic. The betrayer Judas himself fell down at Jesus" feet before the soldiers led Him away to His trial and crucifixion" [2][source]