The dear man was misinformed. A widowed person is free to marry again in the Church.
Amongst many others, my very good Catholic Dad was married in the Church to my stepmother after my mother died.
For biblical source see Matthew 22:23-30:
The same day Sadducees came to him, who say that there is no resurrection; and they asked him a question, saying, “Teacher, Moses said, ‘If a man dies, having no children, his brother must marry the widow, and raise up children for his brother.’ Now there were seven brothers among us; the first married, and died, and having no children left his wife to his brother. So too the second and third, down to the seventh. After them all, the woman died. In the resurrection, therefore, to which of the seven will she be wife? For they all had her.” But Jesus answered them, “You are wrong, because you know neither the scriptures nor the power of God. For in the resurrection they neither marry nor are given in marriage, but are like angels in heaven.”
