This is an easy one for the platform to wiggle around based off the terms and conditions you signed up for when registering on their website.
It is important to note that it is possible that it was truly a network lag (7 seconds is not such a ridiculous time), and you can I expect the site to compensate any resulting situation from network lags.
You can choose to avoid the platform on the basis of its lags and also its unsatisfactory support team.
I agree with you on the fact that the network lag history may not be on the site so support will have a case to prove because the delay may not have originated from the casino network but plays its connection, but as you also mentioned above ops can choose to either avoid the site totally if truly and verified that the lags from the site.
I experience similar thing some time ago when i failed to click on cash out earlier and when it was at critical stage that i clicked it due to lag and other network problem I couldn't get any cash out it has already been taken off before my cash out request got into the system.