The hubbie sounds like he must have used some kind of adapter to plug the trailer into a 240 volt twistlock.
It does sound like he did shoot 240 volts down a leg(s), depending on if it's 30 amp or a 50 amp RV. The converter, television, microwave, and possibly the air/conditioning or control circuits are now toast.
TexasRose, I know you are going to be sick about this. It's a horrible learning experience.
Here are some links to help you understand how RV's utilize only 120 volts, even the 50 amp RV's who can plug into a 120/240 split phase service. The adapter your husband used, instead of utilizing each of the 240 volt service legs separate as 120 volts...instead combined them for 240 volts. A big boo-boo, but one you can get past.
You are going to need dealer/professional help now.
The 30-amp service for an RV is 120-volt with a 3 prong receptacle and a single 30-amp dedicated breaker.
This 50-amp service has 4 wires with two 120-volt HOT feeds.
Almost ALL 50-amp wired RV's use both sides of the service separately as 120 volt on each leg.