Fr. Garrigou-Lagrange was a 20th century teacher of John Paul II and many other Vatican II modernists.
By their fruits you shall know them.
I'd go with another teacher from a better time, there's 19 centuries and innumerable saints to choose from.
Garrigou-Lagrange is a completely orthodox, non-Modernist theologian.
Now you're going to throw out anyone who taught someone who later lost the Faith and/or became a Modernist?
Better throw out St. Thomas Aquinas himself, too!
Give me a break. That's not what Our Lord meant by "judge a tree by its fruits". You can't just use private interpretation on Scripture like that, and ignore all other Catholic principles.
For example, the Catholic Church also teaches: Any teaching is received according to the manner of the receiver." That explains how a good teacher (Garrigou-Lagrange) can teach someone who ends up Modernist (JP2).I could point to all kinds of rotten graduates of Catholic schools. That doesn't mean the Catholic Church is a "bad tree".
JP2 was a bad pupil. Garrigou-Lagrange was a spotless teacher.