I was fired from my first professional job, they told me to find another position elsewhere and gave me severance. I learned from that, what I had done wrong and what to do different in the future. It takes me a lot longer, A LOT LONGER, to understand the unspoken rules. DS is the same and has gotten in trouble at school a lot, learning the rules by crashing into them and learning everything the hard way.
If your DC is fired from this job, talk objectively about what went right and what went wrong, what were the unspoken rules that he picked up in and what were the ones he missed. Did his supervisor expect him to do X or not do Y, etc.
Actually, you should be having these conversations now, evaluate how the week is going, maybe have a weekly check in on Thursday or Friday. Discuss expectations, what the others are doing, job responsibilities and scheduling, etc. Review and plan. So that he can be in the habit of reviewing and evaluating and making changes if needed. Whether he keeps this job all summer or is fired or at any other jobs.