Opinion Sought On Medico-legal Case

I am a Surgeon.I received a legal notice from the Legal team of my former patient WHOM I HAD OPERATED 3 YEARS AGO.I had performed a Resection & Anastomosis of the small intestine for a suspected small bowel tumour.Patient stayed in the hospital for 10 days and was fine at discharge.2 weeks later,he came to me with wound discharge.I diagnosed it as wound infection &gave appropriate antibiotics.The discharge reduced progressively.He made another couple of visits&was lost to follow up.Later,he consulted another Surgeon apparently who diagnosed it as a sinus communicating with the small intestine.He underwent another surgery for the same apparently.I have been accused of 'puncturing the intestine'during the first surgery.