If you are PROFESSOR R.H. Helmholz, you conclude that: “
The argument in canon law was made up of two strands of evidence, both equally important. First that there had been a contract of marriage between Edward and Lady Eleanor Butler (born Talbot) before he married Elizabeth Woodville in May 1464. This would be understood to have consisted of vows exchanged in the present tense, ‘I do marry you’ — no witness or priest was necessary — followed by intercourse. The second fact of Richard’s claim — often forgotten by commentators — was that Edward’s marriage to Elizabeth was clandestine, private, before only a few witnesses, with no banns called and no participation of the king’s ministers.
The fact of the pre-contract cannot now be proved, although it could have been known to many persons in 1483; but there is no doubt that Edward’s marriage to Elizabeth was clandestine. Eleanor Talbot-Butler was not available to testify to the precontract as she had died in 1468. She had in fact died before the boy children of Edward IV were born, and thus under modern law, the adulterous nature of Edward’s second union would have ended before they were born. This did not help their legitimacy in the fifteenth century, however: ‘adultery, when coupled with a present contract of marriage’, was an impediment to the subsequent marriage of the two adulterers. Thus even after Eleanor’s death, Edward could not have married Elizabeth under canon law. This harsh judgement could have been mitigated if Elizabeth had not known of Edward’s prior marriage – in this case the two could have remarried after Eleanor’s death.
But all possible mitigation was rendered irrelevant by the clandestine nature of Edward’s and Elizabeth’s marriage. Although a clandestine marriage was accorded validity in many circumstances and the children born of such a marriage might be considered legitimate, the clandestine nature of this particular marriage actually made the children illegitimate. Clandestine marriages were deplored because people, between whom impediments existed, might contract marriage in error or by fraud; the calling of banns was aimed to publicise a proposed marriage and prevent such misfortunes, and to proclaim the good faith of the contracting parties. Edward’s hasty and secret marriage to Elizabeth proclaimed his bad faith: if the banns had been called and his councillors informed, the impediment of the pre-contract might have been revealed and circumvented.” (Loyalty, Lordship and Law, pp.91-103)
If you are PROFESSOR David Cressy, your conclusions are widely referenced here: https://murreyandblue.wordpress.com/2015/06/25/even-by-tudor-and-stuart-standards-edward-ivs-marriage-to-elizabeth-woodville-was-invalid/
If you are DOCTOR John Ashdown-Hill, you conclude that: “It may also be as well to state very clearly at this point that the relationship which was alleged between Edward IV and Eleanor Talbot in the fifteenth century was neither more nor less than marriage. The Act of Parliament of 1484 is quite explicit on this point (see Appendix 1). The widespread use of the term precontract in relation to this union is not particularly helpful, since its meaning is very frequently misunderstood. It is often taken to mean something like “betrothal”, but this is emphatically not what precontract means. It is, in fact, a legal term which can only be applied retrospectively, the contract to which it refers being precisely a contract of marriage. Such a contract could, of course, only become pre- with hindsight, when viewed in relation to a subsequent, second (and necessarily bigamous) contract of marriage with a third party.” (Eleanor, the Secret Queen, p.103). p. 106 also explains how per verba de futuro could validate a secret marriage at the instant of consummation.
If you are DOCTOR Helen Castor, your conclusions will be very similar, quoted on here: https://www.youtube.com/watch?v=saE-RLwfWpU
Of course, if you are a denialist who can’t be bothered to do any research but just copy sources you know to be dubious, you can form whatever conclusions you like.