They might be; but you have NO proof of who or what actually PERFORMED these 'miracles'.
For false christs and false prophets will appear and perform great signs and miracles to deceive even the elect-if that were possible.
2 Thessalonians 2:9
The coming of the lawless one will be in accordance with the work of Satan displayed in all kinds of counterfeit miracles, signs and wonders.
So ---and I'm sure that you, being a reasonable person, would agree --- one should not be too quick to give credence to a purported miracle unless it has been carefully investigated, both as to its physical aspects (ordinary forensic detective work is often relevant here) and its theological aspects (what does this mean? what is the purported message?)
This is a reliable criterion:
1 Corinthians 12:3
Therefore I want you to know that no one who is speaking by the Spirit of God says, Jesus be cursed, and no one can say, Jesus is Lord, except by the Holy Spirit.
I don't want to speak too soon about this reported Argentinian miracle, since I don't know the extent to which it has received official approval (I guess I should look that up!) --- but it seems to me, at first glance, that the "message" would be nothing more or less than what Our Lord told us:
If it's a Goddamned hoax (literally), then I suppose one could do a kind of exorcism over it, saying "Jesus is Lord," and see if the Goddamned thing blows itself to bleedin' shriekin' smithereens!