There is always a risk that if you raise an issue with a guest re damage/additional payment they will leave you a negative review.
The mind boggles as to what the guest did during their stay that would necessitate the cleaning service needing 'bio-hazard equipment' to clean the bathroom.
What sort of reviews did this guest have previously.
Presumably you have photo's/video's from your cleaning company. If you want to pursue just contact the guest with evidence and remain calm and professional, provided them with the additional bill from the cleaning company and ask him to pay.
Leave an honest review.