Jannie Nel threw a plastic bottle at the World Cup-winning player, and fired some jibes at the perplexed Blues skipper before Bulls wing Bjorn Basson restrained the man.
"I still love South Africa and enjoy coming here," Mealamu said. "It was a once-off incident and it's something that we've seen happen in New Zealand too.
"I wasn't hurt at all, but it was odd and I was caught by surprise by what happened. I can guarantee that it won't happen this weekend."
The Blues have been preparing in Cape Town for Friday's match against the Stormers, where they were rocked by another injury setback.
All Black lock Anthony Boric was ruled out of selection because of a neck injury, joining fellow All Blacks, flank Jerome Kaino, fullback Isaia Toeava and prop Tony Woodcock on the sidelines.
The Blues lost their opening two matches, but bounced back with victory against the Bulls to secure their first win in Pretoria since 2003. The confidence from that result will be carried into the Stormers match where they will face up to one of the best lineouts in the competition without Boric, their major ball winner.
"We've come prepared and we know how dangerous their lineout can be, but we expect guys to step up and that goes for (Boric's replacement) Filo Paulo," Mealamu said.