Glad you asked!
Msg #67:
DM:
Still kneeling, still grimacing, Nordal looks up at the curious tabaxi. "Gaze upon my jars, eh?" He shakes his head. "Well, I suppose you're entitled. Help me to my feet and I will show you."
Nordal was unable to rise to his feet, and as a result was unable to show you where the potions were.
Msg #71:
Therarak Gemfinder:
Therarak reaches into his satchel and pulls out a healing potion and hands it to...
At this point, I was ready to hand the potions over (thinking the potion was going to Nordal)!
Therarak Gemfinder:
...Thorfire.
Here my friend. This will help with your wounds, if you wish.
So now Nordal knows you have healing potions, but still don't offer to help.
That's certainly their prerogative, he thinks,
just as it is mine to not offer what I have in the way of magic items that may assist. Plus, I am still unable to rise from this kneeling position anyway!!!
Msg 72:
DM:
"Your offer is tempting, my good friend," Nordal responds, still kneeling. "Very tempting. However I'm afraid I won't be of much use to you as I am. The last ten hours at the end of that orc's whip have cost me dearly." He tries to stand, but fails, and with clenched teeth returns to a knee.
Basically, if at any point a hand was offered for Nordal to get to his feet, he would have struggled to the cart and gladly given you one or more of the potions. If Therarak had offered him a healing potion, along with Lazaret's persuasion roll, he would've joined the party on their quest! Of course that's easy for me to say because I knew exactly what I was looking for. I tried giving you a couple hints, but didn't want to make it so obvious that you were railroaded into helping.