By broadcasting an old channel state. Using a watchtower can prevent this from happening

If all liquidity is on the other side there must have been an equal amount if sats received in another channel right? So if the "bad actor" closed the channel I don't see how I could lose funds.

2bithits

Routing on the lightning network relies on having payment channels with available liquidity in both directions, so your node may not be able to route payments.

Another thing: you stand to lose funds if all your liquidity is on the other side and a channel is closed, assuming you're dealing with a bad actor.

bitcoin

Relevance of Balancing Channels

Routing on the lightning network relies on having payment channels with available liquidity in both directions, so your node may not be able to route payments.
Another thing: you stand to lose funds if all your liquidity is on the other side and a channel is closed, assuming you're dealing with a bad actor. 