ZOB hand off controller described loss of separation event at FL280 when coordination regarding two opposite direction aircraft was flawed and untimely; reporter suggesting direct RADAR to RADAR controller coordination; in lieu of D-Side coordination; would have been preferable and faster.

Narrative

I was working the Dansville D side. Air Carrier X was a CLE arrival Level at FL280 heading direct CXR. Air Carrier Y was a AVP arrival level at FL290 direct to AVP. Ontario Radar had the hand off on Air Carrier XC; but still on Dansville (DSV) Frequency. Ontario (ONT) Radar Descended Air Carrier Y to FL280 to attempt to avoid a loss of separation with a different aircraft already in ONT airspace; I believe it was Air Carrier Z. This placed Air Carrier Y head on and 15 miles with Air Carrier X. Now is when it gets confusing so I'll do my best to break it up step by step: 1- I realized Air Carrier Y and Air Carrier X were head-on. I called ONT which was online to the D-side. I asked 'which way do you want us to turn Air Carrier X' There was no response.2- Realizing I had the D side I hung up to call the Radar position. Before I made the call; ONT Radar called me. I immediately asked with urgency; 'which way do you want me to turn Air Carrier X?!?' ONT radar response was 'Don't Panic put him on me!'3- I advised the DSV radar that ONT wants to talk to Air Carrier X. This can be heard before I got off the line with ONT Radar from the call in #2.m4- The DSV radar did not switch the Air Carrier X to ONT.5- A few seconds later; ONT D-side called me and said 'take the Air Carrier X down to 260;...pause.... no don't descend him leave him at FL280.' Unknown to me; the DSV radar dialed in to listen to what ONT was saying. After ONT D- side said to take Air Carrier X down to FL260; DSV RADAR immediately hung up and expedited Air Carrier X to FL260. I did not hear the DSV radar controller give this control instruction to Air Carrier X because I was still on the line with ONT D side. 6- I told the DSV radar controller to switch Air Carrier X one more time not knowing he had descended the aircraft.7- Before switching Air Carrier X; DSV radar called ONT radar and said he had descended Air Carrier X to FL260 and turned him 45 degrees left. At this time ONT notified DSV Radar that he had also descended Air Carrier Y. 8- DSV radar instructed Air Carrier X 'stop descent; climb and maintain FL280 expedite!' 9- DSV radar notified Air Carrier X when the traffic was behind him and switched the aircraft to ONT.The first loss of separation with Air Carrier Z and Air Carrier Y was a result of the YYZ arrival and departure route over JHW being head on! I feel that this is an incredibly hazardous arrival and departure route and should be changed immediately! Second in-house calls should be forwarded to the Radar! That way when every second counts there is zero delay and a zero chance of confusion with the messages being relayed between two sets of D sides and R sides! Both incidents today could have been avoided if better procedures were in place.