Padre Pio would not be a saint if the Church had not ruled on it.
There are three steps to sainthood
1 Venerable
2. Blessed (one miracle proven)
3. Saint (at least two miracles proven)
Read Ruffin’s book that An American Mother previously posted about. It is chock full of Padre Pio miracles.
I’m quite aware of the process; I teach courses about it and have written articles on it. My point is that the Church has quite explicitly avoided taking a position on the question of whether the act of canonization enjoys papal infallibility. Many traditionalist Catholics claim that it does, but that is a theological claim that has never been adjudicated by a pope or a council.
And there are good reasons not to go there. A large part of the process of determining whether a person should be canonized, including the assessment of whether a miracle has taken place, rests on human investigation (historical research, medical judgment calls in the case of miracles). In my view it would be foolish to claim infallibility for what necessarily involves exercise of human prudence. And I think most theologians, including some of the greatest doctors of the Church would agree. Only a handful have ever asserted that canonization is an infallible act and they have received from the rest of the greatest doctors of the church a tellingly silent response.
We can say that to the best of our human ability a canonized person is in heaven and to the best of our ability two miracles took place to indicate God’s confirmation of that fact, but we cannot say this is true with the same certainty that we claim the Jesus of Nazareth died and rose from the dead or that he instituted the office of bishop or the Eucharist and the other sacraments or any of the theological teachings that derive from these particular historical facts.