I agree that is annoying when it happens, but it doesn't seem that practical.
Chat is pure chaos as it is, now imagine people constantly thinking they won because they posted the winning bet before others, and then a minute later someone pops in and posts a bet to cancel their win. That's a lot more work for the host, checking every bet and bet time. Also when challenge ends, checking all new ID's because maybe someone got it faster.
Also queue the people just being slow at copying and claiming they were on mobile.
My advice to all mobile users is to play in desktop mode, it's just as fast, maybe even faster to copy and paste that way. I've won probably around 20 challenges on mobile, and never had the issue of copying being too slow.