Present perfect or past perfect?

I have made up the two sets of three similar examples below because my non-native English speaking friends think the examples all have the same answer.

(1a) (Suppose that you saw Bill at a supermarket by chance today. He just left. You are now talking to your friend.)

I say, "I haven't seen Bill for about five years. I was happy to see him again."

(1b) I say, "I hadn't seen Bill for about five years. I was happy to see him again."

(2a) (Suppose that you just ate pizza. You are now talking to your friend.)

I say, "I haven't eaten pizza for months. I was happy to eat it."

(2b) I say, "I hadn't eaten pizza for months. I was happy to eat it."

(3a) (Suppose that you timed your running speed. You just finished your last lap and looked at your stopwatch. You are now talking to your friend.)

I say, "I haven't run so fast for at least six months."

(3b) I say, "I hadn't run so fast for at least six months."

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What confuses me is the correct tense to use for your speaking about something that has just happened.

Most of my non-native English speaking friends think depending on the context, you can use either the present perfect or the pluperfect. In my examples, the pluperfect in all the "b" versions works better. They say that your seeing Bill in (1), your eating pizza in (2) and your running in (3) all happened JUST before your talking to your friend. In other words, your talking is a present action and all of the other actions were done in the recent past.

However, my other friends disagree with them. They think the present perfect in the "a" versions is the better option because it shows a recent change in action. That means, you have just seen Bill in (1), you have just eaten pizza in (2) and you have just run so fast in (3).

I am totally confused. Please explain what the correct tense is. Thank you very much for your time and help.