Inconsistancies / poor research in novels Grrrrr

This winds me up.

I like a good thriller / whodunnit and I thought I'd have a look at Peter James' books so picked a few up while trailing SWMBO around the charity shops.

I'm not going to be able to read them they're so bad so I'm giving them back next time we go to town.

I read one yesterday.

it's set in a rambling old spooky chateau somewhere in France.

Killers after young family in dark etc.

First of all the killer manages to make the battery of the family's car go flat. Not disconnected, flat, it clicks when he tries the ignition. The car is locked, new we are told with 3000 on the clock. When he goes outside again it has vanished.

Now our hero gets himself a kitchen knife and in the pitch dark cuts through an inch thick armoured cable exposing the bare wires with which he electrifies the metal banister thus killing one of the killers. he takes his shotgun and goes downstairs to where the other killer is wounded after he toppled a stuffed deer on her earlier. Except he now has the gun which he covers her with as he retrieves the shotgun.

Is it me? SWMBO says i should chill and enjoy the plot but Dean Koontz doesn't make mistakes like that even with demons from another dimension!