Recently in Yahoo answers I saw this question
Who is responsible for malpractice in plumbing?
I had to reply reply to it as below;
Being a plumber I use snakes (electromechanical machines) regularly.
It does happen; there is no way a plumber can tell what type of joints you have and whether they are properly fitted unless of course they are visible, in which case the accident would not have happened.
In waste fittings there are generally 3 types of joint; solvent weld joints, compression joints and cheap pushfit rubber seal joints. Providing the solvent weld joints have been properly glued this fitting should not cause a problem. Compression joints are a bit iffy dependent upon how much pressure is being put on the snake and the diameter/strength of snake used, and push fit joints are a no no.
If per say it was a solvent weld system it could still be damaged and cause a leak dependent upon the end fitting of the snake, really you shouldn’t use a corkscrew fitting except for specific reasons, better of using something with a bit of a rounded cone shape.
Of course this is presuming its plastic and the plastic is in reasonable condition, unaffected by UV externally or anything else such as sulphuric acid internally. It may be a cast iron system, in which case it may have rusted internally so badly that a spring would find its way thru.
An experienced plumber should be able to spot and identify all the pitfalls, but things do happen and the unexpected can occur.
As for sueing the plumber, really why?
Did you employ the cheapest least experienced plumber around – in which case where was your due diligence? If it was a respectable experienced plumber he would have been acting in your best interest’s and will be able to argue his case. if it was a franchise then i would not rest until they paid up, the so called plumber was likely working in a factory last week and hasn’t yet been trained.
A gallon of water is not likely to cause much damage.
A gallon of dirty water may stain but that can be re painted. Why on earth didn’t someone mop it up with a towel?