Even if it is, so what?
I'm sorry that you were hurt, but seriously, don't obsess over this. Let it go.
If this guy needed such a lame excuse for leaving, imagine the lame excuses he would have conjured up for missing your children's births or not supporting you when there's a death in the family or whatever.
Honestly, I don't understand why people are so taken with the ones who've wronged them, and waste so much emotional energy on them. Be glad he gave you such a lame excuse. Don't be looking for fairness or justice in it. Just kick him to the curb, delete his contact info and block him (in case he drunk dials you at a later date) and move on, secure in the knowledge that nearly anyone you meet will be better.