Service tax in case tour operator and renting of passenger

Fact - The Service Provider is an proprietorship concern registered with service tax department for providing tour operator services on which 70% abatement is available to the service provider thus only 30% of 15% i.e 4.5% Service tax is payable on the value of services provided. Issue- In the case of above mentioned service provider , the service receiver is an private limited company which is considering the service provided to him as renting of motor vehicle and thereby paying the compete service tax itself on reverse charge mechanism basis after taking the abatement of 60%i.e @ 6% and due to such arrangement the service provider is also not filing the service tax return as he is not paying the service tax. Conflict - In this given case what penalties are attracted to the service provider for non-filing of service tax return and whether the payment of service tax by the service receiver hereby will be considered as an default ?