https://www.amnesty.org/en/latest/news/2015/05/gaza-palestinians-tortured-summarily-killed-by-hamas-forces-during-2014-conflict/

In 2014 Amnesty International concluded the hospital was used for torture.

Some were interrogated and tortured or otherwise ill-treated in a disused outpatient’s clinic within the grounds of Gaza City’s main al-Shifa hospital. At least three people arrested during the conflict accused of “collaboration” died in custody.

Doesn’t justify the scale of military action targeting the hospital though.