Because it's easy for somebody to give a casual professional opinion verbally but the real test is if they will write it down and stand over it on a solicitor-client basis. I would take casual advice such as the above with a grain of salt. Just alerting the original poster to the fact that acting on such casual and unauthoritative "advice" could have negative repercussions for them if, in fact, they are deemed to be liable for the outstanding charges after all.