I've run oil levels down in multiple vehicles to where it wasn't even showing on the dipstick with no apparent ill effects, RP is good stuff but not so sure that was much of a factor.
You were in the danger zone where the pump would soon have been pumping hot air instead of oil, then you would have been screwed no matter what brand you use.

 

If thou deny the royal purple gods, thou will be struck down by holy purpleness!

 

wait till purpl sees this lol

 

lol where I hunt its old oil land for like 80 years ago and I found an old wooden well with oil practically to the top of it.....I would have probably poured some crude oil in there till I got to where I could get it changed if it was that low.....(I know crude is not ideal for a motor)
Its funny there's all that oil there and they dont bother pumping it....we even used it for fire starter in a pinch to get the garbage barrel burning in a pinch.
I really think the plan is for the oil companies to sit on much of the US oil till the other countries need it and sell it at a premium then.

 

na, the thing is, there's probably not much oil left there and it would not be cost effective to put in a pumpjack and the required storage facilies to pump it

 

ya know I thought that too but one of my customers is an engery/oil company and they told me their is plenty of oil left there....the reason they stopped pumping it was they raised the costs for pumping it with unrealistic rules and regulations at the time and closed the local refinery down for enviromental reasons (they kinda forced the smaller oil companies out of business...the oil company that owned the rights went bankrupt. they also told me they are going to start pumping again last year there and I saw evidence of it this year a couple miles away...