Although it's quite unkind, on the afternoon of December 3rd, after receiving the order from Digalla to defend Jodhpur to the death, Thompson called Chajit to resign, using the excuse of going to the front line to obtain firsthand information. He left Udaipur and arrived in Jodhpur that same evening.
In fact, this doesn't really count as being opportunistic.
Thompson is a trusted subordinate of Jackson, and he was also sent to Udaipur on Jackson's arrangement, with a status above ordinary military advisers.
Moreover, he is a Newland Army Major, with diplomatic immunity, not subject to Chajit's control.
The key point is that he is not the only adviser assigned to the Southern Battlefield, so even without him, Chajit could find other advisers.
Most crucially, Chajit had already gone to Kota, thus couldn't manage things in Udaipur.
It must be admitted, Thompson's political acumen is very sharp.
To put it this way, this is also why he is trusted by Jackson.
