Nate, I'm wondering if this might be a situation like the one we had with a 6 foot BCI we rescued awhile back (she now lives permanently with Becky from this forum). That snake hadn't been kept right, had likely had some untreated RI's and now has permanent lung damage. She will wheeze a bit sometimes when she's excited or out for a lot of exercise but otherwise is supremely healthy. Our vet explained it's sort of like in humans that have exercise induced asthma (not the same of course but as close as she could relate it for us to understand). We were also told that this snake would always be more suspectible to RI's and to watch her carefully for that. That's one of the reasons we particularily wanted a vet tech to adopt her.

Keep a close eye on this snake, make sure you have a good relationship with an experienced herp vet and don't hesitate for a second to take the snake for re-checks. Be very, very strict on your husbandry especially temps and drafts around the snake and it's home. Seek a second opinion if you are not completely confident in your vet's assessment of the situation.