How is Code 19 tested in Pakistan and can the result be wrong?

Is it possible for a person to be tested positive for the corona virus after death but for someone who bathes their body to not be diagnosed with the virus? One such case is currently a mystery to medical professionals and the local administration in Dera Ismail Khan, Khyber Pakhtunkhwa. A resident died on March 24. Muhammad Amir came to Pakistan from Oman on February 8 and got married on March 23. Local doctors said Amir's health deteriorated a few days before the wedding and he was taken to a local civil hospital where he was sent home after first aid. When his condition worsened, his family took him to Multan for treatment, where he died.
According to doctors, the corona virus was diagnosed in a sample taken from his body after his death. The administration took action and people close to his family involved in the funeral of Mohammad Amir were also tested. However, according to the deputy commissioner of Dera Ismail Khan, none of them were diagnosed with the corona virus. The question here is whether it is possible for the test results of these individuals to fall into the category of 'False Negative' or 'False Positive'? According to Dr. Huma Riaz of the Hematology Department at Lady Reading Hospital in Peshawar, if a person comes in contact with a person who has been diagnosed with the corona virus, it is not necessary for them to be infected. According to him, where 90 out of 100 people will get such an infection, 10 may not. There are two types of coronavirus tests. If a blood sample is taken from you, it means that the antibodies in it will determine if you have the virus in your body. If you have a swab test, a sample is taken from your mouth that is suitable for a 'polymerase chain reaction' or PCR test. Most of the tests in Pakistan are being done with similar kits. Dr. Huma explains that the PCR test compares the sample found in any individual to a 'nun control'. "Noon control" here refers to the genetic sequence of the virus that identifies it. According to him, when the two samples are compared, a sample that is similar to the genetic sequence of the corona virus is declared positive. If the genetic sequence of the sample does not match the sequence of the virus from the Chinese city of Wuhan, it means that it is something else and the result of this test is negative. The Code 19 virus is a SARS-like virus that is already present in various places and has a structure of its own. It is also said that the virus changes its form when it is transmitted from one person to another. But can the result of this test be wrong? Is it possible for a person to have a negative corona virus test and be diagnosed with corona in their body after death? According to Dr. Huma, if the sample is taken correctly, there is very little chance of error in the PCR test. According to him: "If the patient's sample is not taken properly or its quantity is less than required, then a false negative can occur." According to him, there is room for error. However, if the test is positive, the chances of error are reduced because a positive result comes only when the PCR test matches the genetic sequence of the virus. Dr. Muzammil Ahmad Khan of Gomal University's Center for Biochemistry and Biotechnology says that false positives usually occur when a sample taken from a patient is either contaminated (ie not pure), or tested. Devices become contagious or mistakenly match a positive sample to another sample. Even if the person taking the sample is infected with the virus or the person doing the test is infected with the virus, a positive result can still come by mistake. According to Dr. Muzammil, one of the reasons for the false negative may be the low viral load. This means that the amount of virus in the patient is low. According to him, it is possible that in the normal PCR test, the samples of patients with low viral load will be declared negative and when tested on more sensitive devices, they will be positive. Dr Muzammil claims that there have been cases in China where a patient's 'real-time polymerase chain reaction' test or RTPCR test came back negative but more sensitive digital 'droplet chain reaction' test. Or the DDPCR test diagnosed the virus in the same sample.