2001 Ford F-150 ignition coils

My 2001 ford F-150 crew with the 5.4L and 85,000 miles was T-boned in the pass. Side rear door-quarter panel area. The day after I got it back from the body shop, the engine started missing. A couple of miles later it started missing severely. I took it back to the shop and they did the 100,000 mile tune up which did no good. Took it back again and they found that therer were two bad coils. The shop said one has burn marks and had been bad, and the other shorted out from mud and water on it. Neither was accident related, so the other guys insurance refused to pay for the week of rental car and electrical work.($1,100) stating the car wasn't hit in the engine compartment and the shop said the coils went out due to maintanance failure. Before the accident the truck idled smooth and I was getting about 12.5 mpg in town. Now it idles rough and I get less than 10 mpg in town. So I guess my question is could a side impact cause the coils to got bad or any other problems that would kill my milage?