From what I can see, your choice complied with the Catholic church's rule of choosing either one or two baptismal sponsors (872-873) who are required to be Catholic (874 §1), so naturally there were no problems.
Code of Canon Law - IntraText
Apparently your non-Catholic godparent was either recognized as a "witness of the baptism" (874 §2), if they were a baptized non-Catholic Christian, or not recognized by the Catholic church, if they were not a baptized Christian.
Their rules, strictly speaking, apply to "sponsors" and "witnesses". The term of "godparent" is not in the English translation, so I am assuming that Catholic parents can indeed interpret the term any way they want but godparents who are not sponsors or witnesses will not be given any recognition by their church.
Can. 872 Insofar as possible, a person to be baptized is to be given a sponsor who assists an adult in Christian initiation or together with the parents presents an infant for baptism. A sponsor also helps the baptized person to lead a Christian life in keeping with baptism and to fulfill faithfully the obligations inherent in it.
Can. 873 There is to be only one male sponsor or one female sponsor or one of each.
Can. 874 §1. To be permitted to take on the function of sponsor a person must:
1/ be designated by the one to be baptized, by the parents or the person who takes their place, or in their absence by the pastor or minister and have the aptitude and intention of fulfilling this function;
2/ have completed the sixteenth year of age, unless the diocesan bishop has established another age, or the pastor or minister has granted an exception for a just cause;
3/ be a Catholic who has been confirmed and has already received the most holy sacrament of the Eucharist and who leads a life of faith in keeping with the function to be taken on;
4/ not be bound by any canonical penalty legitimately imposed or declared;
5/ not be the father or mother of the one to be baptized.
§2. A baptized person who belongs to a non-Catholic ecclesial community is not to participate except together with a Catholic sponsor and then only as a witness of the baptism.
In those cases, the requirements for godparents were determined by the Calvinist and Lutheran churches respectively, as those were the churches into which those children were being baptized, not by the Catholic church.