(i need to look up which book was last out in Sol's timeline, i don't think he's even going to know about Snape's reasoning for his work. but i think he'll have pegged 'spy' because he's done that shit himself)
oh! okay. the whole HP series was out by Sol's canonpoint, so. he probably does know Snape's backstory, then. buuut he wouldn't use it against him. (and he'll blame Tonks for knowing any details.)
if it's true