I would not worry about it ....
Most likely scenario ... the complaint is without merit and there is no evidence to prove such a thing anyway. The committee makes a show to discourage other offenders and records the name of your player for posterity in case there are other complaints in the future.
Worst case scenario ... your player was playing games with the time. How is the other captain going to prove this? The only worry I would have is if this player has had multiple complaints about this issue.
Bottom line for your grievance committee ... there is no real harm in saying they are considering the complaint. In fact, if word gets out maybe it has a deterrent effect on others. But there is no way they have any hard evidence to make such a decision and award a defaulted court to your opponent based on one complaint alone.
"You should be playing linebacker, not singles."