Craven de Kere wrote:
Conditional is not the criteria, conditional + hypothetical is the criteria.
"If I was rude to you I apologize." = real possibility
"If I were a woman I would have breastacles." = hypothetical
As Craven correctly notes, sometimes using <was> with <if> creates a meaning that points to a real possibility. But it may well still be hypothetical.
"If I was rude to you" CAN = in the speaker's mind,
I was rude to you OR
I expect I was rude to you OR
I probably was rude to you OR
I may have been rude to you OR
I might have been rude to you
All it's saying, [even where the speaker believes he/she was rude] is, "under the condition that I was rude, something follows"; in this case it's "I apologise".
HOWEVER, the vast majority of uses are counterfactual ones because most often, <if S was ...> refers to the identical counterfactual situation that would be meant by <if S were ...>.