The presumption is that a baptism is valid unless there is prudent doubt to the contrary. The Church recognises Church of christ baptisms as being valid and, so if this is the usual method which is followed in the Church of Christ then all good.
As far as the article is concerned, I agree that the author is definitely scrupulous. Although, as it turned out, his baptism wasn’t valid and his concerns should really have warranted a closer consideration, that doesn’t mean that the Church’s approach to recognition of baptisms or ecumenism generally is wrong. As a starting point, the Code of Canon Law states that conditional baptism is not permitted unless, following an investigation, there is a prudent doubt about the fact or validity of the baptism already received. So what he’s arguing for is in fact what the Church already does. However, baptisms in some other denominations are recognised by the Church because of they use the correct matter and form and so, all things being equal, there’s no need for an investigation to tell us what we already know. At the same time of course, ministers in these denominations can and do deviate from the norm leading to the baptisms they perform being invalid. However, unless and until there’s some evidence that this has happened we treat the baptism as valid. In fairness, the author’s pastor should really have checked with a canon lawyer, but that said, tbh I’m surprised that author didn’t ask the canon lawyer he spoke to about “extraordinary baptisms” whether his baptism was valid.
