Whisle Blower advice

any help is nice, i worked for a car wash for over 3 years and worked as an Asst. Manager, i had many job duties, including making sure everybody's punch card was accurate. One day i was manager in charge from open to close which was 730am-6pm, my head manager came in at 1030am, at the end of the day around 4pm, myself and another asst manager were going through the punches on the computer and noticed the Head manager punched in at 830, but didnt get there untill 1030, now usally when we notice this, which was a lot the head manager always told me in advanced why he was punching in for times he wasnt there for, examples like doing paper work at home ect. he always let me know bc it was my job to be on top of everybody's, even his, so on this particualr day we had noticed this and had not recieved any reason why, about 20 minutes later we pulled him into the office and asked him "hey did you do any work at home and punched in early for it today? I noticed you punched in at 830. now remember he has always told me why in advanced but this time, after asking him his response was " i dont have to answer to you" after this i let him know what he was doing was illegal and needs to do what was right by deleting that extra time or i would be contacting the owner and having him deal with the situation. two days later i went to CA for my brothers graduation for the marines, a week later i return to a phone call from the head manager saying hes letting me go, reason un-known. prier to to this i have not had a single write-up or anything to be concidered termination. Does this look like a wrisle blower case???? please help