Sounds like the breaker may have failed. However I don't think the tape had any bearing on the failure, except to indicate which breaker was at fault.
One thing to check is that most mobile homes do not come equipt for an air conditioner. It is usually added in the field. Many HVAC installers will use whatever brand breaker will fit in the panel regardless of listing. Bryant, GE, SqD HO, etc. While they seem to fit they may cause problems, or fires.
I any case it goes down as a fire of electrical origin as if an electrician could be blamed.
Alan--
