Hi Samurai - As Diane explained, depression is a medical condition. it can only be diagnosed by a trained professional. We can't tell you if your husband is clinically depressed or not, and we can't tell you where one incident fits in with his overall health.
You've said that your husband said he was depressed. The next step for someone who believes they are depressed is to seek professional guidance and support from a counselor/therapist and/or a psychiatrist. If that seems too overwhelming, then your family physician or other health care provider would be a good staring point. We wish you and your husband well.
Take good care,