Can a soldier working as a gunner in Iraq convoys, in 2008 earn "ten different distinguishable medals by the US Army"?

It's a bit of a stretch... but you can get quite a few. If they were a gunner in 2008 in Iraq, that means that they will probably an e-4. If they were in Iraq in 2008, then they were there during the search and they were there for 15 months. They may have crossed over three separate campaigns, definitely 2 campaigns. So that could be three Awards... Not really but we'll use our imagination... Then they would have gotten an award for the end of tour, which would be an ARCOM. Plus they would have received the gwot service medal, the National Defense service medal, and they would have the Army Service ribbon from when they joined. If they were a reservist, there would be a Reserves metal with mobilization device. Also, if their unit received a unit award then that would also count.
However, I have been in the Army for 15 years and I only have 12 ribbons, so an e-4 with 10 Awards definitely would set off my BS meter

Capt Bob Abbott as you have it written, sounds suspect. Where did the quote come from? If this is a hiring activity...DD214 will tell the tale. Real question, ok, which ten? Could you have:
1. CAB? Check. Entirely possible. It is a badge and not a Medal.
2. ICM - Campaign Medal for Iraq? Check. As SFC (Join to see) said, may have been different campaigns, just campaign stars added though. Same Medal.
3. GWOT Expeditionary Medal? Not in 2008, maybe from a previous deployment.
4. GWOT Service Medal? Check.
5. ARCOM? Check, very likely. Depending on what happened and what he did, might have a V device.
6. AAM? Check, entirely possible.
7. BSM or higher? Maybe. Again depends on what happened and what he did. If he has a SS, DSC, or MoH, he will be listed by name on the DoD Valor Website. BSM hard to verify.
8. Counting down he Overseas Service Ribbon OSR? Not a Medal, but certainly could have been a 12+ deployment.
9. Purple Heart. Maybe. Depends on what happened. If he has a PH and no CAB/CIB/CMB, suspect. The reverse is possible however.
10. Is it possible to have been awarded two ARCOMs, for different events, same deployment? Sure.
11. Soldier's Medal? Possible, really depends on what happened. If there were a vehicle rollover into a canal and he went into the water to rescue trapped crew or recover people from a burning vehicle or similar.
12. Air Medal: would not be awarded for ground operations. It is possible for non-aviators to have an AM.
13. Reserve Medals: maybe, not really for Iraq service though. They do distinguish between Mobilization and just service.

10 medals for convoys? That's one high-speed 88M or MP.