Pork shoulder on the grill, possible fail....
With all my wisdom, I put a pork shoulder on the grill yesterday morning, Yes, it was 102 here yesterday and the temp inside the grill was 200 before I turned on the gas! At some point in the afternoon the gas ran out without me realizing it. When I caught it, the temp was down to 150 in the closed grill. The max time it may have been off was 2 hours. I replaced the tank and continued cooking, but it did not get over 130 before I had to give up and bring it in at 11pm. I refrigerated it overnight after letting it cool down a bit. Do I toss this and chalk it up as a loss, or do you think I can put it on again today and get some nice pulled pork without getting trichinosis?
Basically, if your figures and temps are accurate, you'll be fine.
Trichinosis is not a worry as long as you bring the temp of the meat to 140 at some point - the stall doesn't worsen the risk. (Incidentally, trichinosis is almost a non-issue with pork nowadays anyway; it's more of an issue with, say, wild boar or bear meat).
150 is actually considered safe air temperature for holding meats. 2 hours at that temperature would not be a problem. Failing to bring the internal temp of the pork above 130 is not a significant problem if you refrigerated the shoulder quickly after grilling and continue cooking it tomorrow. The external temperature is what matters most, because that's where the bacteria are. And the external temperature was surely above 130 for most of the day.
The only potential food safety issue I can think of is if you pierced the meat before grilling, which could hypothetically introduce surface bacteria to the meat's cooler center. But even this is a fairly low risk.
All in all, there is little to be concerned about here. As always, individuals with severe medical issues, severely compromised immune systems, etc, might want to err quite far on the side of caution anyway.