Everyone knows what he meant. Novak lost the match since he broke the rule. Otherwise, he has beaten them all:
2 Nadal
3 Thiem
4 Federer
5 Med
6 Tsitsi
9 Monfils x2
10 RBA
11 Shapo
14 Schwartzman x2
16 Khachanov
19 Garin
21 Raonicx2
25 Ruud
29 Krajinoviv
32 Struff x3
35 Nishioka
Koepfer, Ito, Caruso, Edmund, Dzumhut, Sandgren, Berankis, Kolschreiner, Jaziri, Anderson
What is fascinating is how fast he regrouped afterwards to win in Rome.