First Respons time questions regarding ticket SLA's, Ticket Re-Assignment, and Ticket Closure.

First Respons time questions regarding ticket SLA's, Ticket Re-Assignment, and Ticket Closure.

I am chasing down a few outliers on tickets that my team is reporting to me seen in some of our Zoho Analytics Dashboards with regards to Zoho Desk with regards to First Response Time. 

Our support organization is setup with different SLA's based on three priorities for different support packages based upon first response time. 

Let's say a customer opens a ticket and we do not have enough information to determine their support level, we have a default catch-all SLA that gets applied to all tickets so that time outside our business hours and ticket on hold times do not count towards our time based metrics.  We first respond and later get the support information that triggers a new SLA to apply, does the first response time get cleared?  If the agent then responds again after the new SLA is applied, is it recalculating that as a first response or do both get counted as first responses in the back-end data for the ticket?  What about agent re-assignment, if the first person to touch the ticket responds but then needs to escalate to the next level within the same department in desk and the newly assigned agent responds, does that also count as a first response from the ticket.   Then what about ticket closing, does the first agents response time carry over to the new agent who closed the request? 

We are noticing some odd behavior in the data in analytics where it appears that our frontline teams first response time is getting stuck to the next level agent who closes the request in the ticket closed data and in some cases those Tier II agents also show responses as first response even though they weren't technically the first to respond to the ticket.