You are writing complete rubbish. BMJ does not question the legitimacy of the vaccine trials. With this sentence you are making very serious accusations to healthcare professionals. Most likely you don't even understand how clinical trials work or terminology used in the original article. If BMJ were not a serious journal, nothing in medicine would be serious including those trials.
BMJ is questioning some irregularities brought to the light by a whistle-blower. It shows some evidence confirming issues about one particular clinical research organization and lack of reaction from the FDA. These issues should be addressed and resolved to remove doubts that the data from vaccine trials can be sufficiently trusted.
Also FDA memorandum does not confirm that the FDA has investigated the sites. You probably don't even understand what the quoted professor meant by “oversight”. It definitely is not just checking and fully trusting the submitted paperwork.