WWYD - Paid but transaction not showing up

[Wwydreally]

DH and I took PILs out for dinner whilst on holiday (UK) with them. It was a busy pub restaurant in a popular holiday resort. The food/service was average and with drinks the bill was £135. On ordering DH opened a tab by putting his credit card behind the till (ridiculously old fashioned, but they did swipe it too!). When we finished, he went to the bar to settle the bill and he got a receipt and his card back.

I've just got the credit card bill and it's not showing up! The receipt shows 'account settled'. We're torn between calling them and offering to pay again or just leaving it. I'm worried that someone will have had their pay docked when they realised the difference between the till and the pdq machine.

WWYD really?

What time period is covered by your credit card bill? They're not always bang up to date, so it's possible it'll appear on the next one. I wouldn't offer to pay again until I'd ruled this out.

Can you see the Credit card statement online?
Ours shows when a bill is pending as well as ones they have paid. I've noticed some of the pending ones sit there in that section for a very long time, not showing in paid until at least one statement later.

I've already had the statement and it wasn't anytime near the statement date so no chance of overlap.