A very sticky one this Phil.
not so long ago, bailiffs could use their own discretion.
Today, we have insurance policies to adhere to. Where as at one time if you approached an angler you did not recognise, and he told you that he had forgotten his card, you could ask him a few questions and use your discretion, and then maybe say to him, okay, but I need to see it next time.
Expierience counts for a lot in todays world, as there are many ifs, buts, and maybe's to come to terms with.
Knowing when to give a warning, and when to take action helps also.
And then you have your own welfare to think about. So knowing when to back off helps. But backing off does not mean that is the end of the situation.
If in doubt, Back Off and seek advice, there is allways another day.