Gayle also scored the fastest ever century in the format, with his 100 coming up in just 30 balls. His knock of 175 included 13 fours and 17 sixes.
"I have been honoured to hold that record (highest IPL individual score) and far more delighted that some body as destructive as Chris [Gayle] has now taken over," McCullum told the Times of India.
"I was following Chris's innings on the bus while coming back from practice. It's an unbelievable inning. He is the most powerful batsman in T20 and deserves that record. I knew all along that it would be broken and that it had to be Chris."
Gayle's innings helped his side Royal Challengers Bangalore set the highest ever T20 score of 263, edging out the 260 made by Sri Lanka six years ago.