Here is the way I figure it.
We are not counting my hand as a revealed hand. I can’t remember if I held a club.
So after the flop there are 7 cards revealed, leaving 45 unrevealed.
Peter has the Ace of clubs.
Greg has two small clubs.
The flop has three clubs.
So there are 13 - 6 or only 7 clubs left to be revealed.
Peter has a 7 in 45 chance of seeing a club on the turn.
The odds that Peter will catch another club on the turn are about 15.6 percent
The turn is not a club, so Peter has 7 in 44 on the river or 15.9 percent
So, Peter’s odds of hitting just one club after the flop are 31.4 percent.
They could be a bit higher if you consider that certainly no one who folded after the flop, folded two clubs. I don't remember who was in after the flop. It may have been just me. However, I don't think that does much to change the math.
Peter is the clear underdog.