As noted above, I also don't think the snippet parts of TOS are applicable to you. As does, I can't find any statement on TOS regarding sending on a wrong chain being stated.
Yes, the deposit requirements may not correlate from the complaint sending to different chains but according to part of the writing the TOS emphasizes that anyone should never make a mistake and must carefully send to the right address and "probably" also with the right chain.
But how did he take the deposit address on the gambling site, he should have confirmed the address and chain because not all different chains get support for deposits to gambling platforms.