The Gospel of Mark which is seen by most scholars as the first written Gospel (circa 70's CE) is chock full of spiritual allegory. The fleeing naked young man is just one of many that's mistaken as historical kernels of truth.
Mark 14:48-52
"48 And Jesus answered and said unto them, Are ye come out, as against a thief, with swords and with staves to take me?
49 I was daily with you in the temple teaching, and ye took me not: but the scriptures must be fulfilled.
50 And they all forsook him, and fled.
51 And there followed him a certainyoung man, having a linen cloth cast about his naked body; and theyoung manlaid hold on him:
52 And he left the linen cloth, and fled from them naked."
Now who's this young man covered with common linen cloth which easily sheds away?
Mark 16:3-8
"3 And they said among themselves, Who shall roll us away the stone from the door of the sepulchre?
4 And when they looked, they saw that the stone was rolled away: for it was very great.
5 And entering into the sepulchre, they saw ayoung mansitting on the right side, clothed in a long white garment; and they were affrighted.
6 And he saith unto them, Be not affrighted: Ye seek Jesus of Nazareth, which was crucified: he is risen; he is not here: behold the place where they laid him.
7 But go your way, tell his disciples and Peter that he goeth before you into Galilee: there shall ye see him, as he said unto you.
8 And they went out quickly, and fled from the sepulchre; for they trembled and were amazed: neither said they any thing to any man; for they were afraid."
Now who's this young man wearing an uncommonly clean, and luxurious white Robe?
Now the argument for the hypothetical "Q" makes it look like a single document. In reality the unknown authors of the canonical Gospels drew on many sources, and some we no longer have. As for the young men in Mark we can see the spiritual meaning, and it's inspiration from Paul.
1 Corinthians 15:47-53 (circa 50's CE)
"47 The first man is of the earth, earthy; the second man is the Lord from heaven.
48 As is the earthy, such are they also that are earthy: and as is the heavenly, such are they also that are heavenly.
49 And as we have borne the image of the earthy, we shall also bear the image of the heavenly.
50 Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.
51 Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,
52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
53 For this corruptible must put on incorruption, and this mortal must put on immortality."
The garment of the young man fleeing Jesus represents the Earthly flesh that decays, and the empty Tomb young man's garment represents Heavenly flesh that's incorruptible.
When you have scholars looking at the Gospels as if it was history embellished instead of the parable within parables that it is? Then no wonder said scholars cannot see how useless the Gospels are for determining Jesus's historicity.