It's all fun and games when you are doing what you love while getting paid for it, but that all changes when you have to start keeping track of finances. When I was just starting out and making a part time income, I wasn't too concerned about it, but it has grown to a point where I have to start thinking about tax time.
What if your employer reimburses you for the loss? No offset of an otherwise nondeductible loss against the reimbursement, because they're separate transactions. The loss stays nondeductible. Nor is it permissible to include the reimbursement as part of the selling price and avail yourself of the exclusion.