We are always warned when cooking with dry spices (e.g. chilli powder, cumin, coriander etc.) not to let the spices burn when cooking as they will turn bitter. If one wishes to use a dry rub (e.g. garlic powder or curry powder) what is the best way to seal the meat yet at the same time not burn the spices? If you keep the oil temperature low so as not to burn the spices, surely you will not achieve the temperature required to kick off the Maillard reaction? Or is that the whole point of using a dry rub? (I'm thinking here of meat that is partially coated with spices rather than with a thick coating or dredge sealing the meat completely). 
The simple answer is you don't sear after rubbing, because you can't prevent spices from burning. You use a dry rub method for low to medium temperature cooking. You are probably confusing maillard reactions and caramelization. Maillard reactions happen at a lower temperature, starting at 120°C, low and slow cooking is what develops them. Caramelization starts with sucrose sugars at about 160°C. You could in theory sear, then rub spices on meat, however that will mostly prevent the flavors from penetrating. 