No way that's a single tri tip. The largest one I've ever seen was a hair over 3.5lbs untrimmed. If they are peeled and neatly trimmed, they are usually between 1.5 and 2.25lbs each. Unpeeled and untrimmed, around 2.25-3lbs each.
Sirloin tip roast is far more likely in this case, or 2-3 tri tips. If one piece of meat in there, it is NOT tri tip.
Modded Brinkmann Gourmet. Basic UDS. Rescued 22.5" OTS. SJS Mini-WSM. Stubbs. B&B Oak Lump.
Cannondale 2009 F8 (for burning off all the great BBQ)