Hi Iaaklat, if the airline completed his line training then there may have been a financial penalty if he left the airline before completing his contract. As a line trainer myself I know it costs a lot of money and takes a great deal of effort to line train new pilots. This cost and effort is commercial risk to the airline, especially as the pilot is non-productive whilst undergoing such training (due to the presence of a safety pilot). In a previous employment I worked for an airline that hired self-sponsored first officers. Their line training was provided. These first officers had to fly for a set minimum period with the airline so that it could recover it's investment. Such pilots were subject to a financial penalty for not comleting the set minimum contract (post line training). Therefore, it is likely that the bonding element of his contract reflects this risk. I would imagine that in scenarios where agencies are involved, such risk is passed on to them and hence on to the contractor. This should have been clearly laid out in his contract with Rishworth - up-front.
All I can say is that anybody should think very carefully when considering such a contract (knowing the facts) and not commit unless they are prepared to go the distance. There are other options available (that typically include base training but not line training) as ratings can be purchased directly from third parties such as GECAT and CAE for most types.