All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Every Muslim must choose proper words and expressions when speaking about what is glorified under the Sharee‘ah (Islamic law), as is the case when speaking about Allaah The Exalted, His angels, His Books, His Messengers, etc. This is the implementation of the honorable verse where Allaah The Almighty Says (what means): {That [has been commanded], and whoever honors the sacred ordinances of Allah - it is best for him in the sight of his Lord.} [Quran 22:30]
With regard to the issue in question, it is well-known that the attributes of Allaah The Almighty must be confined to what is mentioned in the Sharee‘ah. Thus, it is not permissible to describe Allaah The Almighty with any attributes except those He has described Himself with, or those His Messenger, sallallaahu ‘alayhi was sallam, described Him with.
If the speaker meant, by describing Allaah the Almighty as the first artist, that He is the Maker and the Creator of the universe and the One Who has arranged it perfectly without any precedent, then this meaning is true, although the expression is wrong.
However, if he meant what you described, which cannot be said by a Muslim, this is complete disbelief, which expels him from Islam (we ask Allaah The Almighty for refuge from that).
Allaah Knows best.