Is a person's testimony about witnessing an event they did not see themselves considered false testimony, even if the event was real?

If you testify to something that did not happen, such as your going with a relative’s friend and his speaking with the tenant, then this is a false testimony, and it is one of the gravest major sins because it causes rights to be lost. On the authority of Abu Bakrah and Anas, the Prophet, peace and blessings be upon him, said: “Shall I not inform you of the greatest of the major sins, three times?” They said: “Yes, O Messenger of Allah.” He said: “Associating partners with Allah, and disrespecting parents.” He then sat up, having been reclining, and said: “And indeed, false speech.” He kept repeating it until we said: “Would that he had stopped.” False testimony is when a person testifies to what he does not know, even if it matches reality. It is not permissible to give it under the pretext of lack of compensation, and the witness must only testify to what he knows.