These air leaks do often resolve on their own as long as the chicken is not behaving sickly. The other form of this is called air sacculitis and is caused by bacteria. It can be serious and life threatening. But this case points to a spontaneous occurrence with spontaneous resolution. If it does recur with the rooster acting sick, get him on an antibiotic as soon as possible.
It's unlikely it will happen again, though.
It's unlikely it will happen again, though.