my husbands company witheld funds for repair bill after accident

My husband was involved in an accident a week ago. Just his truck hitting a guard rail, only he was injured (whiplash so far)

His company informed him its inconclusive of if hes even at fault but they told him they have withheld a portion of his check to cover "repair costs".

We have gone through every paper hes signed for this company but NOTHING is stated regarding this in any paperwork.

Is this legal in Colorado or anywhere??
Thank you