Bankruptcy administrators are obliged to monetise the bankrupt's assets including patents. This might most conveniently occur through sale of the patent to a third party, but if no-one wants to buy it the administrator is obliged to enforce the patent against potential licensees. If the startup offered a license can afford neither to license it nor to litigate it, the administrator is likely, if it takes the matter to court, to obtain the startup business and it's assets as it stands. In this situation the only strategy available to the startup owner to avoid losing the business is to threaten to spend all assets attempting to defend the suit until the business is worthless, in which event the administrator will see a negative asset value due to unrecoverable legal costs. But this is a dangerous bluff if considered as such and called. I've heard of once such case where a US small software business owner took this line and lost everything in the process.