Condensate drain line

Did an inspection on a home with a crawlspace today where the condensate drain line empties into a 2" PVC pipe with a p-trap that runs approx. 10’ and is connected to the main horizontal waste line that runs out the side of the foundation wall. Is this OK? I call them out when they are directly connected to the waste pipe. Does the P-trap make it OK? What if the P-trap dries out? What if the sewer line backs up. There is no air gap where the condensate line enters the PVC pipe. Doesn’t look right to me, not sure. Thoughts? Thanks, Stan

if the p trap can dry out it is not ok