Employing self employed people

[kiwi pom]

now lets take about real life on farm

My guess is 'real life on the farm' means you employ a self employed person to do an employee's job, to avoid the cost and hassle of an employee.
If they break something I don't really see why they should pay for it, the good news is being self employed you can just instantly stop using them and hire someone else.
Might be different if you're hiring a company to come in and do a specific job, building a shed maybe, and they happen to be using some of your equipment that they then damage.