The situation is expertly explained in this article
The article draws a distinction between when you dismiss for misconduct and when you dismiss for incapacity. Either "method" can be used, but different principles apply to each "method".
I have given you the article mainly for further reference.
It seems that you have followed the path of misconduct and in this instance, you are not out of the woods, unfortunately. I cannot find any procedural unfairness from the information you provided. He was given a notice of a disciplinary hearing and was allowed to present his case, which basically cannot be anything other than an explanation on why he was not at work.
With regards XXXXX XXXXX substantive unfairness, since you have followed the misconduct route, if he was incarcerated for the whole two weeks, you might have some trouble. If he was out of prison for any time during the time that he did not pitch for work, the dismissal was substantively fair, since he could have come to work but stayed away.
Also, if there was a way to contact you and inform you that he is absent, this can also be used in establishing whether the dismissal is substantively fair.
The fact that he was arrested on drug related charges does not assist you in any way, unfortunately, since he is not convicted yet and deemed innocent until proved guilty.
You, unfortunately, have no other option but to appear at the conciliation and/or arbitration. If you fail to show, they are going to find in his favor by default. You need to show that the dismissal was both substantively and procedurally fair. With the latter, I think your are fine, but with the former, it is a bit murky for me at this stage. Like I said, if he could have contacted you or at any stage, was out of jail and could come to work, then, substantively, the dismissal would be fair. If not, it is going to be touch and go, unfortunately.
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