An interesting syncope!

So as we all know you usually get, or I do, some interesting stuff on an overtime shift. Did a night shift down south on Tuesday, luckily there was an officer from a station I've worked at before doing a roster there to help out with a staffing shortage (where doesn't have one of those?) and I worked with him. We responded to 5 jobs (god I was bored, not like the 8 or 10 I would have in town).

One of our jobs went like this,

A mature male, Unconscious/Near fainting.
O/a - Pt is supine on his bed, GSC=15, BP=124/80, PR=84, RR=22, ECG=normal sinus rhythm (textbook perfect), SpO2=98%, BGL=6.1, no cardiac history, no medications and no allergies.
The story goes that he jumped out of bed to visit the toilet and got as far as the hallway before collapsing, I suspect there was some LOC as he further states, that he came to and got up and collapsed again.
This time the wife heard the thud and got out of bed herself and made him wait before assisting him to bed. He was feeling a pounding, rapid pulse with associated nausea. So I explained the thing about getting upright to quick,,, and that from sleep this is compounded by the resting state of the body and it's regulatory mechanisms,,, etc.

I allow ten minutes and start postural BP measurements with stethoscope and brachial measurement, no palpated radial cheapo/shoddy job.

Sitting=110mmHg, Standing he's sweating, panting and looking green around the gills with a systolic <80mmHg, put him back on the bed supine, started some O2 and waited 15-20 minutes to give his body more time to wake up and return to normal but similar BPs were recorded with the next attempts and so he got transported.

An hour later at hospital after dodging the glare of the triage nurse for bringing in a healthy syncope, the pt was maintaining a standing BP=110mmHg systolic with no change in ECG, pulse or GCS.
He was discharged two hours or so later with bloods having been taken but no results.
I know I did right but what do you guys an' gals think might have been wrong with him and could I have done anything else?

Be careful out there and I'll see you at the big one,

Taz