Looks like he was using a 15 foot rod. 100 feet cast were no problem
The longest cast was 54 meters, this is 177 feet, which is a long way with a 15 ft rod.
With a long rod you can lift 100 feet +, then shoot the rest once you get it right. I used to throw a Mk 1 Grand Spey line on my 16 footer, this was 100 ft head, once you add in the polytips, tippet, & rod length then it was 130 feet before shooting the running line on the cast (I only threw about another 15/16 feet). It was a full line, but if I'd cut it behind the head & looped it to nylon running running line then it would have been interesting to see how much further I could have shot it, but then you'd be back to the issues with tangles in the running line I suppose as fishing conditions in the real world are a bit more tricky than a casting pool.
Not sure my shoulders would stand up to it now, that's why I made the swap to Scandi heads & a 15 footer is a long as I go now & that only when necessary, usually a 14 footer is my default setting, less in low water or smaller rivers.
I still enjoy digging the big rods out now and again though, it reminds you that body rotation & weight transfer are vital to casting properly.