So I was working an employee tournament for a company today and had a situation I think I would handle differently if I had had the opportunity. This was a fairly informal, friendly match (unsanctioned, working as a dual) and no one had really outlined a substitution procedure so teams just subbed as they pleased (only at stoppages however). So at a stoppage a player tells me "ref I'm going off on this side" (the far side) and he steps off. Well, no one comes on for him so as play restarts he comes back on. He then receives a pass and crosses it into the box where a teammate heads it in. The opposing team goes nuts arguing that they stopped marking him because he said he was off. At the time I didn't think much of it but now I'm realizing I should have at least disallowed the goal. Any thoughts?